21177492 has 48 divisors (see below), whose sum is σ = 57412992. Its totient is φ = 5950080.

The previous prime is 21177487. The next prime is 21177493. The reversal of 21177492 is 29477112.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21177493) 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, 3058 + ... + 7190.

It is an arithmetic number, because the mean of its divisors is an integer number (1196104).

Almost surely, 2^21177492 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21177492, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28706496).

21177492 is an abundant number, since it is smaller than the sum of its proper divisors (36235500).

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

21177492 is a wasteful number, since it uses less digits than its factorization.

21177492 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4208 (or 4206 counting only the distinct ones).

The product of its digits is 7056, while the sum is 33.

The square root of 21177492 is about 4601.9009115799. The cubic root of 21177492 is about 276.6675189084.

The spelling of 21177492 in words is "twenty-one million, one hundred seventy-seven thousand, four hundred ninety-two".