21642088 has 32 divisors (see below), whose sum is σ = 46274760. Its totient is φ = 9400320.

The previous prime is 21642067. The next prime is 21642107. The reversal of 21642088 is 88024612.

It can be written as a sum of positive squares in 4 ways, for example, as 15382084 + 6260004 = 3922^2 + 2502^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4353 + ... + 7888.

Almost surely, 2^21642088 is an apocalyptic number.

It is an amenable number.

21642088 is an abundant number, since it is smaller than the sum of its proper divisors (24632672).

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

21642088 is a wasteful number, since it uses less digits than its factorization.

21642088 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12277 (or 12273 counting only the distinct ones).

The product of its (nonzero) digits is 6144, while the sum is 31.

The square root of 21642088 is about 4652.1057597608. The cubic root of 21642088 is about 278.6760970942.

The spelling of 21642088 in words is "twenty-one million, six hundred forty-two thousand, eighty-eight".