21468540 has 24 divisors (see below), whose sum is σ = 60112080. Its totient is φ = 5724928.

The previous prime is 21468539. The next prime is 21468563. The reversal of 21468540 is 4586412.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a junction number, because it is equal to n+sod(n) for n = 21468498 and 21468507.

It is a congruent number.

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, 178845 + ... + 178964.

It is an arithmetic number, because the mean of its divisors is an integer number (2504670).

Almost surely, 2^21468540 is an apocalyptic number.

21468540 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21468540 is an abundant number, since it is smaller than the sum of its proper divisors (38643540).

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

21468540 is a wasteful number, since it uses less digits than its factorization.

21468540 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 357821 (or 357819 counting only the distinct ones).

The product of its (nonzero) digits is 7680, while the sum is 30.

The square root of 21468540 is about 4633.4155867999. The cubic root of 21468540 is about 277.9291954319.

The spelling of 21468540 in words is "twenty-one million, four hundred sixty-eight thousand, five hundred forty".