21592040 has 64 divisors (see below), whose sum is σ = 52079760. Its totient is φ = 8028160.

The previous prime is 21592019. The next prime is 21592073. The reversal of 21592040 is 4029512.

It can be written as a sum of positive squares in 8 ways, for example, as 7409284 + 14182756 = 2722^2 + 3766^2 .

It is a junction number, because it is equal to n+sod(n) for n = 21591997 and 21592015.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 76700 + ... + 76980.

Almost surely, 2^21592040 is an apocalyptic number.

21592040 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21592040, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26039880).

21592040 is an abundant number, since it is smaller than the sum of its proper divisors (30487720).

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

21592040 is a wasteful number, since it uses less digits than its factorization.

21592040 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 422 (or 418 counting only the distinct ones).

The product of its (nonzero) digits is 720, while the sum is 23.

The square root of 21592040 is about 4646.7235768873. The cubic root of 21592040 is about 278.4611155847.

The spelling of 21592040 in words is "twenty-one million, five hundred ninety-two thousand, forty".