21979294 has 8 divisors (see below), whose sum is σ = 32989320. Its totient is φ = 10982856.

The previous prime is 21979289. The next prime is 21979297. The reversal of 21979294 is 49297912.

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

It is a self number, because there is not a number n which added to its sum of digits gives 21979294.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21979297) by changing a digit.

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, 3252 + ... + 7384.

It is an arithmetic number, because the mean of its divisors is an integer number (4123665).

Almost surely, 2^21979294 is an apocalyptic number.

21979294 is a deficient number, since it is larger than the sum of its proper divisors (11010026).

21979294 is a wasteful number, since it uses less digits than its factorization.

21979294 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6794.

The product of its digits is 81648, while the sum is 43.

The square root of 21979294 is about 4688.2079732026. The cubic root of 21979294 is about 280.1159978564.

The spelling of 21979294 in words is "twenty-one million, nine hundred seventy-nine thousand, two hundred ninety-four".