20951317 has 8 divisors (see below), whose sum is σ = 21248000. Its totient is φ = 20656944.

The previous prime is 20951309. The next prime is 20951323. The reversal of 20951317 is 71315902.

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 20951317 - 2³ = 20951309 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20951347) 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, 24859 + ... + 25687.

It is an arithmetic number, because the mean of its divisors is an integer number (2656000).

Almost surely, 2^20951317 is an apocalyptic number.

It is an amenable number.

20951317 is a deficient number, since it is larger than the sum of its proper divisors (296683).

20951317 is a wasteful number, since it uses less digits than its factorization.

20951317 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1155.

The product of its (nonzero) digits is 1890, while the sum is 28.

The square root of 20951317 is about 4577.2608621314. The cubic root of 20951317 is about 275.6790579093.

The spelling of 20951317 in words is "twenty million, nine hundred fifty-one thousand, three hundred seventeen".