20615998 has 16 divisors (see below), whose sum is σ = 33727680. Its totient is φ = 9393696.

The previous prime is 20615977. The next prime is 20616017. The reversal of 20615998 is 89951602.

It is a self number, because there is not a number n which added to its sum of digits gives 20615998.

It is a congruent number.

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, 2965 + ... + 7072.

It is an arithmetic number, because the mean of its divisors is an integer number (2107980).

Almost surely, 2^20615998 is an apocalyptic number.

20615998 is a deficient number, since it is larger than the sum of its proper divisors (13111682).

20615998 is a wasteful number, since it uses less digits than its factorization.

20615998 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10131.

The product of its (nonzero) digits is 38880, while the sum is 40.

The square root of 20615998 is about 4540.4843353986. The cubic root of 20615998 is about 274.2004234490.

The spelling of 20615998 in words is "twenty million, six hundred fifteen thousand, nine hundred ninety-eight".