21379450 has 24 divisors (see below), whose sum is σ = 40739580. Its totient is φ = 8342400.

The previous prime is 21379441. The next prime is 21379453. The reversal of 21379450 is 5497312.

It can be written as a sum of positive squares in 6 ways, for example, as 8982009 + 12397441 = 2997^2 + 3521^2 .

It is not an unprimeable number, because it can be changed into a prime (21379453) 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 in 11 ways as a sum of consecutive naturals, for example, 3165 + ... + 7264.

Almost surely, 2^21379450 is an apocalyptic number.

21379450 is a deficient number, since it is larger than the sum of its proper divisors (19360130).

21379450 is a wasteful number, since it uses less digits than its factorization.

21379450 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10482 (or 10477 counting only the distinct ones).

The product of its (nonzero) digits is 7560, while the sum is 31.

The square root of 21379450 is about 4623.7917340642. The cubic root of 21379450 is about 277.5442128510.

The spelling of 21379450 in words is "twenty-one million, three hundred seventy-nine thousand, four hundred fifty".