21012396 has 12 divisors (see below), whose sum is σ = 49028952. Its totient is φ = 7004128.

The previous prime is 21012373. The next prime is 21012401. The reversal of 21012396 is 69321012.

It is a tau number, because it is divible by the number of its divisors (12).

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 875505 + ... + 875528.

It is an arithmetic number, because the mean of its divisors is an integer number (4085746).

Almost surely, 2^21012396 is an apocalyptic number.

It is an amenable number.

21012396 is an abundant number, since it is smaller than the sum of its proper divisors (28016556).

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

21012396 is a wasteful number, since it uses less digits than its factorization.

21012396 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1751040 (or 1751038 counting only the distinct ones).

The product of its (nonzero) digits is 648, while the sum is 24.

The square root of 21012396 is about 4583.9280099059. The cubic root of 21012396 is about 275.9466920780.

The spelling of 21012396 in words is "twenty-one million, twelve thousand, three hundred ninety-six".