20720715 has 8 divisors (see below), whose sum is σ = 33153168. Its totient is φ = 11051040.

The previous prime is 20720681. The next prime is 20720717. The reversal of 20720715 is 51702702.

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

It is not a de Polignac number, because 20720715 - 2⁸ = 20720459 is a prime.

It is a super-2 number, since 2×20720715² = 858696060222450, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (20720717) 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, 690676 + ... + 690705.

It is an arithmetic number, because the mean of its divisors is an integer number (4144146).

Almost surely, 2^20720715 is an apocalyptic number.

20720715 is a deficient number, since it is larger than the sum of its proper divisors (12432453).

20720715 is a wasteful number, since it uses less digits than its factorization.

20720715 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1381389.

The product of its (nonzero) digits is 980, while the sum is 24.

The square root of 20720715 is about 4552.0012082599. The cubic root of 20720715 is about 274.6638979269.

The spelling of 20720715 in words is "twenty million, seven hundred twenty thousand, seven hundred fifteen".