21532940 has 48 divisors (see below), whose sum is σ = 53131680. Its totient is φ = 7226880.

The previous prime is 21532937. The next prime is 21532943. The reversal of 21532940 is 4923512.

It is an interprime number because it is at equal distance from previous prime (21532937) and next prime (21532943).

It is a Harshad number since it is a multiple of its sum of digits (26).

It is not an unprimeable number, because it can be changed into a prime (21532943) 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, 905 + ... + 6624.

It is an arithmetic number, because the mean of its divisors is an integer number (1106910).

Almost surely, 2^21532940 is an apocalyptic number.

21532940 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21532940 is an abundant number, since it is smaller than the sum of its proper divisors (31598740).

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

21532940 is a wasteful number, since it uses less digits than its factorization.

21532940 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7562 (or 7560 counting only the distinct ones).

The product of its (nonzero) digits is 2160, while the sum is 26.

The square root of 21532940 is about 4640.3598998354. The cubic root of 21532940 is about 278.2068229568.

The spelling of 21532940 in words is "twenty-one million, five hundred thirty-two thousand, nine hundred forty".