20531616 has 48 divisors (see below), whose sum is σ = 61596864. Its totient is φ = 5865984.

The previous prime is 20531603. The next prime is 20531657. The reversal of 20531616 is 61613502.

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

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

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, 14605 + ... + 15948.

It is an arithmetic number, because the mean of its divisors is an integer number (1283268).

Almost surely, 2^20531616 is an apocalyptic number.

It is an amenable number.

20531616 is an abundant number, since it is smaller than the sum of its proper divisors (41065248).

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

20531616 is a wasteful number, since it uses less digits than its factorization.

20531616 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 30573 (or 30565 counting only the distinct ones).

The product of its (nonzero) digits is 1080, while the sum is 24.

The square root of 20531616 is about 4531.1826270853. The cubic root of 20531616 is about 273.8258079077.

The spelling of 20531616 in words is "twenty million, five hundred thirty-one thousand, six hundred sixteen".