21532506 has 32 divisors (see below), whose sum is σ = 45800640. Its totient is φ = 6725376.

The previous prime is 21532501. The next prime is 21532513. The reversal of 21532506 is 60523512.

It is a zygodrome in base 11.

It is not an unprimeable number, because it can be changed into a prime (21532501) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 38380 + ... + 38936.

It is an arithmetic number, because the mean of its divisors is an integer number (1431270).

Almost surely, 2^21532506 is an apocalyptic number.

21532506 is an abundant number, since it is smaller than the sum of its proper divisors (24268134).

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

21532506 is a wasteful number, since it uses less digits than its factorization.

21532506 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 958.

The product of its (nonzero) digits is 1800, while the sum is 24.

The square root of 21532506 is about 4640.3131359855. The cubic root of 21532506 is about 278.2049538426.

The spelling of 21532506 in words is "twenty-one million, five hundred thirty-two thousand, five hundred six".