20612640 has 48 divisors (see below), whose sum is σ = 64931328. Its totient is φ = 5496576.

The previous prime is 20612639. The next prime is 20612659. The reversal of 20612640 is 4621602.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (48).

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 20992 + ... + 21951.

It is an arithmetic number, because the mean of its divisors is an integer number (1352736).

Almost surely, 2^20612640 is an apocalyptic number.

20612640 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20612640 is an abundant number, since it is smaller than the sum of its proper divisors (44318688).

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

20612640 is a wasteful number, since it uses less digits than its factorization.

20612640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 42961 (or 42953 counting only the distinct ones).

The product of its (nonzero) digits is 576, while the sum is 21.

The square root of 20612640 is about 4540.1145360002. The cubic root of 20612640 is about 274.1855350919.

The spelling of 20612640 in words is "twenty million, six hundred twelve thousand, six hundred forty".