20657812 has 18 divisors (see below), whose sum is σ = 42053802. Its totient is φ = 8853264.

The previous prime is 20657801. The next prime is 20657821. The reversal of 20657812 is 21875602.

It can be written as a sum of positive squares in only one way, i.e., 15256836 + 5400976 = 3906^2 + 2324^2 .

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 52503 + ... + 52894.

Almost surely, 2^20657812 is an apocalyptic number.

It is an amenable number.

20657812 is an abundant number, since it is smaller than the sum of its proper divisors (21395990).

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

20657812 is a wasteful number, since it uses less digits than its factorization.

20657812 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 105415 (or 105406 counting only the distinct ones).

The product of its (nonzero) digits is 6720, while the sum is 31.

The square root of 20657812 is about 4545.0865778333. The cubic root of 20657812 is about 274.3856788305.

The spelling of 20657812 in words is "twenty million, six hundred fifty-seven thousand, eight hundred twelve".