21970887 has 8 divisors (see below), whose sum is σ = 29316720. Its totient is φ = 14636160.

The previous prime is 21970867. The next prime is 21970891. The reversal of 21970887 is 78807912.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 21970887 - 2⁷ = 21970759 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21970867) 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 7 ways as a sum of consecutive naturals, for example, 4789 + ... + 8177.

It is an arithmetic number, because the mean of its divisors is an integer number (3664590).

Almost surely, 2^21970887 is an apocalyptic number.

21970887 is a deficient number, since it is larger than the sum of its proper divisors (7345833).

21970887 is a wasteful number, since it uses less digits than its factorization.

21970887 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5553.

The product of its (nonzero) digits is 56448, while the sum is 42.

The square root of 21970887 is about 4687.3112762009. The cubic root of 21970887 is about 280.0802788518.

The spelling of 21970887 in words is "twenty-one million, nine hundred seventy thousand, eight hundred eighty-seven".