21039410 has 48 divisors (see below), whose sum is σ = 44525376. Its totient is φ = 7011264.

The previous prime is 21039401. The next prime is 21039439. The reversal of 21039410 is 1493012.

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 196577 + ... + 196683.

It is an arithmetic number, because the mean of its divisors is an integer number (927612).

Almost surely, 2^21039410 is an apocalyptic number.

21039410 is an abundant number, since it is smaller than the sum of its proper divisors (23485966).

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

21039410 is a wasteful number, since it uses less digits than its factorization.

21039410 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 227 (or 174 counting only the distinct ones).

The product of its (nonzero) digits is 216, while the sum is 20.

The square root of 21039410 is about 4586.8736629648. The cubic root of 21039410 is about 276.0648958230.

The spelling of 21039410 in words is "twenty-one million, thirty-nine thousand, four hundred ten".