20513812 has 24 divisors (see below), whose sum is σ = 39809952. Its totient is φ = 9170400.

The previous prime is 20513791. The next prime is 20513819. The reversal of 20513812 is 21831502.

It is a Harshad number since it is a multiple of its sum of digits (22).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20513819) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1138 + ... + 6505.

It is an arithmetic number, because the mean of its divisors is an integer number (1658748).

Almost surely, 2^20513812 is an apocalyptic number.

20513812 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

It is an amenable number.

20513812 is a deficient number, since it is larger than the sum of its proper divisors (19296140).

20513812 is a wasteful number, since it uses less digits than its factorization.

20513812 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7719 (or 7717 counting only the distinct ones).

The product of its (nonzero) digits is 480, while the sum is 22.

The square root of 20513812 is about 4529.2175924767. The cubic root of 20513812 is about 273.7466356279.

The spelling of 20513812 in words is "twenty million, five hundred thirteen thousand, eight hundred twelve".