20403688 has 16 divisors (see below), whose sum is σ = 38494080. Its totient is φ = 10138608.

The previous prime is 20403589. The next prime is 20403709. The reversal of 20403688 is 88630402.

It is a happy number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6520 + ... + 9127.

It is an arithmetic number, because the mean of its divisors is an integer number (2405880).

Almost surely, 2^20403688 is an apocalyptic number.

It is an amenable number.

20403688 is a deficient number, since it is larger than the sum of its proper divisors (18090392).

20403688 is a wasteful number, since it uses less digits than its factorization.

20403688 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15816 (or 15812 counting only the distinct ones).

The product of its (nonzero) digits is 9216, while the sum is 31.

The square root of 20403688 is about 4517.0441662663. The cubic root of 20403688 is about 273.2559064189.

The spelling of 20403688 in words is "twenty million, four hundred three thousand, six hundred eighty-eight".