21974160 has 80 divisors (see below), whose sum is σ = 73370304. Its totient is φ = 5408256.

The previous prime is 21974119. The next prime is 21974179. The reversal of 21974160 is 6147912.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (80).

It is a Harshad number since it is a multiple of its sum of digits (30).

It is an unprimeable number.

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 15 ways as a sum of consecutive naturals, for example, 402 + ... + 6641.

Almost surely, 2^21974160 is an apocalyptic number.

21974160 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21974160, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (36685152).

21974160 is an abundant number, since it is smaller than the sum of its proper divisors (51396144).

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

21974160 is a wasteful number, since it uses less digits than its factorization.

21974160 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7072 (or 7066 counting only the distinct ones).

The product of its (nonzero) digits is 3024, while the sum is 30.

The square root of 21974160 is about 4687.6603972558. The cubic root of 21974160 is about 280.0941860014.

The spelling of 21974160 in words is "twenty-one million, nine hundred seventy-four thousand, one hundred sixty".