20621616 has 40 divisors (see below), whose sum is σ = 55591680. Its totient is φ = 6574656.

The previous prime is 20621609. The next prime is 20621677. The reversal of 20621616 is 61612602.

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

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 8236 + ... + 10443.

It is an arithmetic number, because the mean of its divisors is an integer number (1389792).

Almost surely, 2^20621616 is an apocalyptic number.

It is an amenable number.

20621616 is an abundant number, since it is smaller than the sum of its proper divisors (34970064).

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

20621616 is a wasteful number, since it uses less digits than its factorization.

20621616 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18713 (or 18707 counting only the distinct ones).

The product of its (nonzero) digits is 864, while the sum is 24.

The square root of 20621616 is about 4541.1029497249. The cubic root of 20621616 is about 274.2253283485.

The spelling of 20621616 in words is "twenty million, six hundred twenty-one thousand, six hundred sixteen".