20431616 has 18 divisors (see below), whose sum is σ = 40783932. Its totient is φ = 10215680.

The previous prime is 20431591. The next prime is 20431627. The reversal of 20431616 is 61613402.

It is a happy number.

It is a junction number, because it is equal to n+sod(n) for n = 20431591 and 20431600.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39650 + ... + 40161.

It is an arithmetic number, because the mean of its divisors is an integer number (2265774).

Almost surely, 2^20431616 is an apocalyptic number.

It is an amenable number.

20431616 is a deficient number, since it is larger than the sum of its proper divisors (20352316).

20431616 is an frugal number, since it uses more digits than its factorization.

20431616 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 79827 (or 79813 counting only the distinct ones).

The product of its (nonzero) digits is 864, while the sum is 23.

The square root of 20431616 is about 4520.1345112729. The cubic root of 20431616 is about 273.3805246036.

The spelling of 20431616 in words is "twenty million, four hundred thirty-one thousand, six hundred sixteen".