21974331 has 4 divisors (see below), whose sum is σ = 29299112. Its totient is φ = 14649552.

The previous prime is 21974321. The next prime is 21974357. The reversal of 21974331 is 13347912.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 21974331 - 2⁵ = 21974299 is a prime.

It is a super-2 number, since 2×21974331² = 965742445795122, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21974321) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3662386 + ... + 3662391.

It is an arithmetic number, because the mean of its divisors is an integer number (7324778).

Almost surely, 2^21974331 is an apocalyptic number.

21974331 is a deficient number, since it is larger than the sum of its proper divisors (7324781).

21974331 is an equidigital number, since it uses as much as digits as its factorization.

21974331 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7324780.

The product of its digits is 4536, while the sum is 30.

The square root of 21974331 is about 4687.6786365962. The cubic root of 21974331 is about 280.0949125514.

The spelling of 21974331 in words is "twenty-one million, nine hundred seventy-four thousand, three hundred thirty-one".