21488634 has 24 divisors (see below), whose sum is σ = 46661940. Its totient is φ = 7147008.

The previous prime is 21488609. The next prime is 21488641. The reversal of 21488634 is 43688412.

21488634 is a `hidden beast` number, since 2 + 14 + 8 + 8 + 634 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 20930625 + 558009 = 4575^2 + 747^2 .

It is a super-2 number, since 2×21488634² = 923522782371912, which contains 22 as substring.

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 9352 + ... + 11420.

Almost surely, 2^21488634 is an apocalyptic number.

21488634 is an abundant number, since it is smaller than the sum of its proper divisors (25173306).

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

21488634 is a wasteful number, since it uses less digits than its factorization.

21488634 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2654 (or 2651 counting only the distinct ones).

The product of its digits is 36864, while the sum is 36.

The square root of 21488634 is about 4635.5834584225. The cubic root of 21488634 is about 278.0158799134.

It can be divided in two parts, 21488 and 634, that added together give a palindrome (22122).

The spelling of 21488634 in words is "twenty-one million, four hundred eighty-eight thousand, six hundred thirty-four".