21690410 has 32 divisors (see below), whose sum is σ = 44917632. Its totient is φ = 7387200.

The previous prime is 21690407. The next prime is 21690413. The reversal of 21690410 is 1409612.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (21690407) and next prime (21690413).

It is not an unprimeable number, because it can be changed into a prime (21690413) 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, 10460 + ... + 12360.

It is an arithmetic number, because the mean of its divisors is an integer number (1403676).

Almost surely, 2^21690410 is an apocalyptic number.

21690410 is an abundant number, since it is smaller than the sum of its proper divisors (23227222).

21690410 is a wasteful number, since it uses less digits than its factorization.

21690410 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2078.

The product of its (nonzero) digits is 432, while the sum is 23.

The square root of 21690410 is about 4657.2964260395. The cubic root of 21690410 is about 278.8833503013.

The spelling of 21690410 in words is "twenty-one million, six hundred ninety thousand, four hundred ten".