21972785 has 8 divisors (see below), whose sum is σ = 26980800. Its totient is φ = 17169264.

The previous prime is 21972763. The next prime is 21972803. The reversal of 21972785 is 58727912.

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

It is a cyclic number.

It is not a de Polignac number, because 21972785 - 2⁸ = 21972529 is a prime.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 50885 + ... + 51314.

It is an arithmetic number, because the mean of its divisors is an integer number (3372600).

Almost surely, 2^21972785 is an apocalyptic number.

It is an amenable number.

21972785 is a deficient number, since it is larger than the sum of its proper divisors (5008015).

21972785 is a wasteful number, since it uses less digits than its factorization.

21972785 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 102247.

The product of its digits is 70560, while the sum is 41.

The square root of 21972785 is about 4687.5137333132. The cubic root of 21972785 is about 280.0883437221.

The spelling of 21972785 in words is "twenty-one million, nine hundred seventy-two thousand, seven hundred eighty-five".