21447464 has 16 divisors (see below), whose sum is σ = 40269300. Its totient is φ = 10708992.

The previous prime is 21447427. The next prime is 21447509. The reversal of 21447464 is 46474412.

It can be written as a sum of positive squares in 2 ways, for example, as 21252100 + 195364 = 4610^2 + 442^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 21447464.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6632 + ... + 9320.

Almost surely, 2^21447464 is an apocalyptic number.

It is an amenable number.

21447464 is a deficient number, since it is larger than the sum of its proper divisors (18821836).

21447464 is a wasteful number, since it uses less digits than its factorization.

21447464 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3692 (or 3688 counting only the distinct ones).

The product of its digits is 21504, while the sum is 32.

The square root of 21447464 is about 4631.1406802212. The cubic root of 21447464 is about 277.8382165140.

The spelling of 21447464 in words is "twenty-one million, four hundred forty-seven thousand, four hundred sixty-four".