21065796 has 36 divisors (see below), whose sum is σ = 53388972. Its totient is φ = 7003584.

The previous prime is 21065783. The next prime is 21065797. The reversal of 21065796 is 69756012.

It can be written as a sum of positive squares in 2 ways, for example, as 6320196 + 14745600 = 2514^2 + 3840^2 .

It is a tau number, because it is divible by the number of its divisors (36).

It is a super-2 number, since 2×21065796² = 887535522227232, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a self number, because there is not a number n which added to its sum of digits gives 21065796.

It is not an unprimeable number, because it can be changed into a prime (21065797) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 26866 + ... + 27638.

It is an arithmetic number, because the mean of its divisors is an integer number (1483027).

Almost surely, 2^21065796 is an apocalyptic number.

It is an amenable number.

21065796 is an abundant number, since it is smaller than the sum of its proper divisors (32323176).

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

21065796 is a wasteful number, since it uses less digits than its factorization.

21065796 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1540 (or 1535 counting only the distinct ones).

The product of its (nonzero) digits is 22680, while the sum is 36.

The square root of 21065796 is about 4589.7490127457. The cubic root of 21065796 is about 276.1802540221.

The spelling of 21065796 in words is "twenty-one million, sixty-five thousand, seven hundred ninety-six".