21945286 has 48 divisors (see below), whose sum is σ = 38782800. Its totient is φ = 9289280.

The previous prime is 21945277. The next prime is 21945293. The reversal of 21945286 is 68254912.

It is a hoax number, since the sum of its digits (37) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 371925 + ... + 371983.

It is an arithmetic number, because the mean of its divisors is an integer number (807975).

Almost surely, 2^21945286 is an apocalyptic number.

21945286 is a deficient number, since it is larger than the sum of its proper divisors (16837514).

21945286 is a wasteful number, since it uses less digits than its factorization.

21945286 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 165 (or 154 counting only the distinct ones).

The product of its digits is 34560, while the sum is 37.

The square root of 21945286 is about 4684.5795969329. The cubic root of 21945286 is about 279.9714511709.

The spelling of 21945286 in words is "twenty-one million, nine hundred forty-five thousand, two hundred eighty-six".