21739464 has 48 divisors (see below), whose sum is σ = 62344620. Its totient is φ = 6819840.

The previous prime is 21739453. The next prime is 21739469. The reversal of 21739464 is 46493712.

It can be written as a sum of positive squares in 2 ways, for example, as 21622500 + 116964 = 4650^2 + 342^2 .

It is a Harshad number since it is a multiple of its sum of digits (36).

It is not an unprimeable number, because it can be changed into a prime (21739469) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 7657 + ... + 10104.

Almost surely, 2^21739464 is an apocalyptic number.

21739464 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

21739464 is an abundant number, since it is smaller than the sum of its proper divisors (40605156).

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

21739464 is a wasteful number, since it uses less digits than its factorization.

21739464 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17790 (or 17783 counting only the distinct ones).

The product of its digits is 36288, while the sum is 36.

The square root of 21739464 is about 4662.5598119488. The cubic root of 21739464 is about 279.0934284551.

The spelling of 21739464 in words is "twenty-one million, seven hundred thirty-nine thousand, four hundred sixty-four".