1201555512 has 256 divisors, whose sum is σ = 3788467200. Its totient is φ = 350760960.

The previous prime is 1201555499. The next prime is 1201555513. The reversal of 1201555512 is 2155551021.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1201555513) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 3462523 + ... + 3462869.

It is an arithmetic number, because the mean of its divisors is an integer number (14798700).

Almost surely, 2^1201555512 is an apocalyptic number.

1201555512 is a gapful number since it is divisible by the number (12) 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 1201555512, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1894233600).

1201555512 is an abundant number, since it is smaller than the sum of its proper divisors (2586911688).

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

1201555512 is a wasteful number, since it uses less digits than its factorization.

1201555512 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 443 (or 433 counting only the distinct ones).

The product of its (nonzero) digits is 2500, while the sum is 27.

The square root of 1201555512 is about 34663.4607620186. The cubic root of 1201555512 is about 1063.1175315272.

The spelling of 1201555512 in words is "one billion, two hundred one million, five hundred fifty-five thousand, five hundred twelve".