21516994 has 8 divisors (see below), whose sum is σ = 32316480. Its totient is φ = 10744836.

The previous prime is 21516961. The next prime is 21517021. The reversal of 21516994 is 49961512.

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

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, 4734 + ... + 8089.

It is an arithmetic number, because the mean of its divisors is an integer number (4039560).

Almost surely, 2^21516994 is an apocalyptic number.

21516994 is a deficient number, since it is larger than the sum of its proper divisors (10799486).

21516994 is a wasteful number, since it uses less digits than its factorization.

21516994 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13664.

The product of its digits is 19440, while the sum is 37.

The square root of 21516994 is about 4638.6413959262. The cubic root of 21516994 is about 278.1381315855.

The spelling of 21516994 in words is "twenty-one million, five hundred sixteen thousand, nine hundred ninety-four".