21239410 has 16 divisors (see below), whose sum is σ = 38880000. Its totient is φ = 8351536.

The previous prime is 21239381. The next prime is 21239429. The reversal of 21239410 is 1493212.

It is a super-2 number, since 2×21239410² = 902225074296200, which contains 22 as substring.

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, 17410 + ... + 18589.

It is an arithmetic number, because the mean of its divisors is an integer number (2430000).

Almost surely, 2^21239410 is an apocalyptic number.

21239410 is a deficient number, since it is larger than the sum of its proper divisors (17640590).

21239410 is a wasteful number, since it uses less digits than its factorization.

21239410 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 36065.

The product of its (nonzero) digits is 432, while the sum is 22.

The square root of 21239410 is about 4608.6234387287. The cubic root of 21239410 is about 276.9368934425.

The spelling of 21239410 in words is "twenty-one million, two hundred thirty-nine thousand, four hundred ten".