21117974 has 8 divisors (see below), whose sum is σ = 32769360. Its totient is φ = 10194856.

The previous prime is 21117959. The next prime is 21117983. The reversal of 21117974 is 47971112.

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 21117974.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 181994 + ... + 182109.

It is an arithmetic number, because the mean of its divisors is an integer number (4096170).

Almost surely, 2^21117974 is an apocalyptic number.

21117974 is a deficient number, since it is larger than the sum of its proper divisors (11651386).

21117974 is a wasteful number, since it uses less digits than its factorization.

21117974 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 364134.

The product of its digits is 3528, while the sum is 32.

The square root of 21117974 is about 4595.4296861121. The cubic root of 21117974 is about 276.4080902073.

The spelling of 21117974 in words is "twenty-one million, one hundred seventeen thousand, nine hundred seventy-four".