21455372 has 6 divisors (see below), whose sum is σ = 37546908. Its totient is φ = 10727684.

The previous prime is 21455363. The next prime is 21455383. The reversal of 21455372 is 27355412.

It is a happy number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2681918 + ... + 2681925.

It is an arithmetic number, because the mean of its divisors is an integer number (6257818).

Almost surely, 2^21455372 is an apocalyptic number.

It is an amenable number.

21455372 is a deficient number, since it is larger than the sum of its proper divisors (16091536).

21455372 is a wasteful number, since it uses less digits than its factorization.

21455372 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5363847 (or 5363845 counting only the distinct ones).

The product of its digits is 8400, while the sum is 29.

The square root of 21455372 is about 4631.9943868705. The cubic root of 21455372 is about 277.8723600167.

The spelling of 21455372 in words is "twenty-one million, four hundred fifty-five thousand, three hundred seventy-two".