21349472 has 12 divisors (see below), whose sum is σ = 42031836. Its totient is φ = 10674720.

The previous prime is 21349459. The next prime is 21349511. The reversal of 21349472 is 27494312.

It is a Harshad number since it is a multiple of its sum of digits (32), and also a Moran number because the ratio is a prime number: 667171 = 21349472 / (2 + 1 + 3 + 4 + 9 + 4 + 7 + 2).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 333554 + ... + 333617.

It is an arithmetic number, because the mean of its divisors is an integer number (3502653).

Almost surely, 2^21349472 is an apocalyptic number.

It is an amenable number.

21349472 is a deficient number, since it is larger than the sum of its proper divisors (20682364).

21349472 is an equidigital number, since it uses as much as digits as its factorization.

21349472 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 667181 (or 667173 counting only the distinct ones).

The product of its digits is 12096, while the sum is 32.

The square root of 21349472 is about 4620.5488851434. The cubic root of 21349472 is about 277.4144291524.

The spelling of 21349472 in words is "twenty-one million, three hundred forty-nine thousand, four hundred seventy-two".