20917712 has 20 divisors (see below), whose sum is σ = 41085540. Its totient is φ = 10315008.

The previous prime is 20917711. The next prime is 20917717. The reversal of 20917712 is 21771902.

It can be written as a sum of positive squares in 2 ways, for example, as 10523536 + 10394176 = 3244^2 + 3224^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20917711) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 7787 + ... + 10122.

It is an arithmetic number, because the mean of its divisors is an integer number (2054277).

Almost surely, 2^20917712 is an apocalyptic number.

It is an amenable number.

20917712 is a deficient number, since it is larger than the sum of its proper divisors (20167828).

20917712 is a wasteful number, since it uses less digits than its factorization.

20917712 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17990 (or 17984 counting only the distinct ones).

The product of its (nonzero) digits is 1764, while the sum is 29.

The square root of 20917712 is about 4573.5885254360. The cubic root of 20917712 is about 275.5315866345.

The spelling of 20917712 in words is "twenty million, nine hundred seventeen thousand, seven hundred twelve".