21338456 has 8 divisors (see below), whose sum is σ = 40009620. Its totient is φ = 10669224.

The previous prime is 21338441. The next prime is 21338467. The reversal of 21338456 is 65483312.

It is a tau number, because it is divible by the number of its divisors (8).

It is a congruent number.

It is an unprimeable number.

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, 1333646 + ... + 1333661.

Almost surely, 2^21338456 is an apocalyptic number.

It is an amenable number.

21338456 is a deficient number, since it is larger than the sum of its proper divisors (18671164).

21338456 is a wasteful number, since it uses less digits than its factorization.

21338456 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2667313 (or 2667309 counting only the distinct ones).

The product of its digits is 17280, while the sum is 32.

The square root of 21338456 is about 4619.3566651645. The cubic root of 21338456 is about 277.3667070804.

It can be divided in two parts, 213 and 38456, that multiplied together give a triangular number (8191128 = T₄₀₄₇).

The spelling of 21338456 in words is "twenty-one million, three hundred thirty-eight thousand, four hundred fifty-six".