21370917 has 8 divisors (see below), whose sum is σ = 28547424. Its totient is φ = 14220848.

The previous prime is 21370913. The next prime is 21370927. The reversal of 21370917 is 71907312.

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

It is a cyclic number.

It is not a de Polignac number, because 21370917 - 2² = 21370913 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21370913) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4638 + ... + 8015.

It is an arithmetic number, because the mean of its divisors is an integer number (3568428).

Almost surely, 2^21370917 is an apocalyptic number.

It is an amenable number.

21370917 is a deficient number, since it is larger than the sum of its proper divisors (7176507).

21370917 is a wasteful number, since it uses less digits than its factorization.

21370917 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13219.

The product of its (nonzero) digits is 2646, while the sum is 30.

The square root of 21370917 is about 4622.8689144297. The cubic root of 21370917 is about 277.5072833086.

The spelling of 21370917 in words is "twenty-one million, three hundred seventy thousand, nine hundred seventeen".