21379516 has 6 divisors (see below), whose sum is σ = 37414160. Its totient is φ = 10689756.

The previous prime is 21379493. The next prime is 21379517. The reversal of 21379516 is 61597312.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21379517) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2672436 + ... + 2672443.

Almost surely, 2^21379516 is an apocalyptic number.

It is an amenable number.

21379516 is a deficient number, since it is larger than the sum of its proper divisors (16034644).

21379516 is a wasteful number, since it uses less digits than its factorization.

21379516 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5344883 (or 5344881 counting only the distinct ones).

The product of its digits is 11340, while the sum is 34.

The square root of 21379516 is about 4623.7988710583. The cubic root of 21379516 is about 277.5444984507.

The spelling of 21379516 in words is "twenty-one million, three hundred seventy-nine thousand, five hundred sixteen".