21974907 has 4 divisors (see below), whose sum is σ = 29299880. Its totient is φ = 14649936.

The previous prime is 21974899. The next prime is 21974917. The reversal of 21974907 is 70947912.

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

It is not a de Polignac number, because 21974907 - 2³ = 21974899 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21974917) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3662482 + ... + 3662487.

It is an arithmetic number, because the mean of its divisors is an integer number (7324970).

Almost surely, 2^21974907 is an apocalyptic number.

21974907 is a deficient number, since it is larger than the sum of its proper divisors (7324973).

21974907 is an equidigital number, since it uses as much as digits as its factorization.

21974907 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7324972.

The product of its (nonzero) digits is 31752, while the sum is 39.

The square root of 21974907 is about 4687.7400738522. The cubic root of 21974907 is about 280.0973598502.

The spelling of 21974907 in words is "twenty-one million, nine hundred seventy-four thousand, nine hundred seven".