21970971 has 24 divisors (see below), whose sum is σ = 35742720. Its totient is φ = 12884400.

The previous prime is 21970969. The next prime is 21970981. The reversal of 21970971 is 17907912.

It is not a de Polignac number, because 21970971 - 2¹ = 21970969 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21970901) 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 23 ways as a sum of consecutive naturals, for example, 511 + ... + 6648.

It is an arithmetic number, because the mean of its divisors is an integer number (1489280).

Almost surely, 2^21970971 is an apocalyptic number.

21970971 is a deficient number, since it is larger than the sum of its proper divisors (13771749).

21970971 is a wasteful number, since it uses less digits than its factorization.

21970971 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7207 (or 7204 counting only the distinct ones).

The product of its (nonzero) digits is 7938, while the sum is 36.

The square root of 21970971 is about 4687.3202365531. The cubic root of 21970971 is about 280.0806357895.

The spelling of 21970971 in words is "twenty-one million, nine hundred seventy thousand, nine hundred seventy-one".