21579474 has 64 divisors (see below), whose sum is σ = 52254720. Its totient is φ = 5808000.

The previous prime is 21579469. The next prime is 21579479. The reversal of 21579474 is 47497512.

It is an interprime number because it is at equal distance from previous prime (21579469) and next prime (21579479).

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (21579479) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 85849 + ... + 86099.

It is an arithmetic number, because the mean of its divisors is an integer number (816480).

Almost surely, 2^21579474 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21579474, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26127360).

21579474 is an abundant number, since it is smaller than the sum of its proper divisors (30675246).

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

21579474 is a wasteful number, since it uses less digits than its factorization.

21579474 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 375.

The product of its digits is 70560, while the sum is 39.

The square root of 21579474 is about 4645.3712445831. The cubic root of 21579474 is about 278.4070860843.

The spelling of 21579474 in words is "twenty-one million, five hundred seventy-nine thousand, four hundred seventy-four".