21540610 has 32 divisors (see below), whose sum is σ = 47722752. Its totient is φ = 6816960.

The previous prime is 21540599. The next prime is 21540611. The reversal of 21540610 is 1604512.

It is not an unprimeable number, because it can be changed into a prime (21540611) 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, 10926 + ... + 12745.

It is an arithmetic number, because the mean of its divisors is an integer number (1491336).

Almost surely, 2^21540610 is an apocalyptic number.

21540610 is an abundant number, since it is smaller than the sum of its proper divisors (26182142).

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

21540610 is a wasteful number, since it uses less digits than its factorization.

21540610 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23698.

The product of its (nonzero) digits is 240, while the sum is 19.

The square root of 21540610 is about 4641.1862707717. The cubic root of 21540610 is about 278.2398513159.

The spelling of 21540610 in words is "twenty-one million, five hundred forty thousand, six hundred ten".