21325540 has 24 divisors (see below), whose sum is σ = 44876160. Its totient is φ = 8512608.

The previous prime is 21325511. The next prime is 21325553. The reversal of 21325540 is 4552312.

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, 13639 + ... + 15121.

It is an arithmetic number, because the mean of its divisors is an integer number (1869840).

Almost surely, 2^21325540 is an apocalyptic number.

21325540 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21325540 is an abundant number, since it is smaller than the sum of its proper divisors (23550620).

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

21325540 is a wasteful number, since it uses less digits than its factorization.

21325540 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2211 (or 2209 counting only the distinct ones).

The product of its (nonzero) digits is 1200, while the sum is 22.

The square root of 21325540 is about 4617.9584233728. The cubic root of 21325540 is about 277.3107331548.

Adding to 21325540 its reverse (4552312), we get a palindrome (25877852).

The spelling of 21325540 in words is "twenty-one million, three hundred twenty-five thousand, five hundred forty".