1212578640 has 640 divisors, whose sum is σ = 5332992000. Its totient is φ = 246343680.

The previous prime is 1212578603. The next prime is 1212578659. The reversal of 1212578640 is 468752121.

1212578640 is a `hidden beast` number, since 1 + 2 + 1 + 2 + 5 + 7 + 8 + 640 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 1212578595 and 1212578604.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 6093261 + ... + 6093459.

It is an arithmetic number, because the mean of its divisors is an integer number (8332800).

Almost surely, 2^1212578640 is an apocalyptic number.

1212578640 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1212578640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2666496000).

1212578640 is an abundant number, since it is smaller than the sum of its proper divisors (4120413360).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1212578640 is a wasteful number, since it uses less digits than its factorization.

1212578640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 272 (or 260 counting only the distinct ones).

The product of its (nonzero) digits is 26880, while the sum is 36.

The square root of 1212578640 is about 34822.0998792434. The cubic root of 1212578640 is about 1066.3586706245.

The spelling of 1212578640 in words is "one billion, two hundred twelve million, five hundred seventy-eight thousand, six hundred forty".