20864615 has 8 divisors (see below), whose sum is σ = 25062480. Its totient is φ = 16675072.

The previous prime is 20864609. The next prime is 20864617. The reversal of 20864615 is 51646802.

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 20864615 - 2¹⁴ = 20848231 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20864617) 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, 7256 + ... + 9714.

It is an arithmetic number, because the mean of its divisors is an integer number (3132810).

Almost surely, 2^20864615 is an apocalyptic number.

20864615 is a deficient number, since it is larger than the sum of its proper divisors (4197865).

20864615 is a wasteful number, since it uses less digits than its factorization.

20864615 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4161.

The product of its (nonzero) digits is 11520, while the sum is 32.

The square root of 20864615 is about 4567.7800954074. The cubic root of 20864615 is about 275.2982549191.

The spelling of 20864615 in words is "twenty million, eight hundred sixty-four thousand, six hundred fifteen".