21376644 has 48 divisors (see below), whose sum is σ = 51374400. Its totient is φ = 6915456.

The previous prime is 21376627. The next prime is 21376651. The reversal of 21376644 is 44667312.

It is a happy number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 77034 + ... + 77310.

It is an arithmetic number, because the mean of its divisors is an integer number (1070300).

Almost surely, 2^21376644 is an apocalyptic number.

It is an amenable number.

21376644 is an abundant number, since it is smaller than the sum of its proper divisors (29997756).

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

21376644 is a wasteful number, since it uses less digits than its factorization.

21376644 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 452 (or 450 counting only the distinct ones).

The product of its digits is 24192, while the sum is 33.

The square root of 21376644 is about 4623.4882934858. The cubic root of 21376644 is about 277.5320699889.

The spelling of 21376644 in words is "twenty-one million, three hundred seventy-six thousand, six hundred forty-four".