20480640 has 64 divisors (see below), whose sum is σ = 65288160. Its totient is φ = 5460992.

The previous prime is 20480639. The next prime is 20480657. The reversal of 20480640 is 4608402.

It is a tau number, because it is divible by the number of its divisors (64).

It is a super-2 number, since 2×20480640² = 838913229619200, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (24).

It is a self number, because there is not a number n which added to its sum of digits gives 20480640.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3414 + ... + 7253.

Almost surely, 2^20480640 is an apocalyptic number.

20480640 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20480640 is an abundant number, since it is smaller than the sum of its proper divisors (44807520).

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

20480640 is a wasteful number, since it uses less digits than its factorization.

20480640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10689 (or 10677 counting only the distinct ones).

The product of its (nonzero) digits is 1536, while the sum is 24.

The square root of 20480640 is about 4525.5541097196. The cubic root of 20480640 is about 273.5990013985.

The spelling of 20480640 in words is "twenty million, four hundred eighty thousand, six hundred forty".