21972586 has 8 divisors (see below), whose sum is σ = 33376320. Its totient is φ = 10847148.

The previous prime is 21972553. The next prime is 21972593. The reversal of 21972586 is 68527912.

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

It is a super-3 number, since 3×21972586³ (a number of 23 digits) contains 333 as substring.

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 3 ways as a sum of consecutive naturals, for example, 69376 + ... + 69691.

It is an arithmetic number, because the mean of its divisors is an integer number (4172040).

Almost surely, 2^21972586 is an apocalyptic number.

21972586 is a deficient number, since it is larger than the sum of its proper divisors (11403734).

21972586 is a wasteful number, since it uses less digits than its factorization.

21972586 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 139148.

The product of its digits is 60480, while the sum is 40.

The square root of 21972586 is about 4687.4925066607. The cubic root of 21972586 is about 280.0874981648.

The spelling of 21972586 in words is "twenty-one million, nine hundred seventy-two thousand, five hundred eighty-six".