21172494 has 32 divisors (see below), whose sum is σ = 50065920. Its totient is φ = 5840352.

The previous prime is 21172483. The next prime is 21172499. The reversal of 21172494 is 49427112.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21172499) 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, 7474 + ... + 9909.

It is an arithmetic number, because the mean of its divisors is an integer number (1564560).

Almost surely, 2^21172494 is an apocalyptic number.

21172494 is an abundant number, since it is smaller than the sum of its proper divisors (28893426).

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

21172494 is a wasteful number, since it uses less digits than its factorization.

21172494 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17424.

The product of its digits is 4032, while the sum is 30.

The square root of 21172494 is about 4601.3578430720. The cubic root of 21172494 is about 276.6457521972.

The spelling of 21172494 in words is "twenty-one million, one hundred seventy-two thousand, four hundred ninety-four".