21392210 has 16 divisors (see below), whose sum is σ = 44006976. Its totient is φ = 7334448.

The previous prime is 21392197. The next prime is 21392213. The reversal of 21392210 is 1229312.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (21392213) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 152732 + ... + 152871.

It is an arithmetic number, because the mean of its divisors is an integer number (2750436).

Almost surely, 2^21392210 is an apocalyptic number.

21392210 is an abundant number, since it is smaller than the sum of its proper divisors (22614766).

21392210 is a wasteful number, since it uses less digits than its factorization.

21392210 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 305617.

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

The square root of 21392210 is about 4625.1713481773. The cubic root of 21392210 is about 277.5994178856.

The spelling of 21392210 in words is "twenty-one million, three hundred ninety-two thousand, two hundred ten".