21311392 has 12 divisors (see below), whose sum is σ = 41956866. Its totient is φ = 10655680.

The previous prime is 21311347. The next prime is 21311393. The reversal of 21311392 is 29311312.

It can be written as a sum of positive squares in only one way, i.e., 14107536 + 7203856 = 3756^2 + 2684^2 .

It is not an unprimeable number, because it can be changed into a prime (21311393) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 332959 + ... + 333022.

Almost surely, 2^21311392 is an apocalyptic number.

It is an amenable number.

21311392 is a deficient number, since it is larger than the sum of its proper divisors (20645474).

21311392 is an equidigital number, since it uses as much as digits as its factorization.

21311392 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 665991 (or 665983 counting only the distinct ones).

The product of its digits is 324, while the sum is 22.

The square root of 21311392 is about 4616.4263234671. The cubic root of 21311392 is about 277.2493941813.

The spelling of 21311392 in words is "twenty-one million, three hundred eleven thousand, three hundred ninety-two".