20820715 has 8 divisors (see below), whose sum is σ = 25015680. Its totient is φ = 16636032.

The previous prime is 20820697. The next prime is 20820721. The reversal of 20820715 is 51702802.

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 20820715 - 2⁷ = 20820587 is a prime.

It is a super-2 number, since 2×20820715² = 867004346222450, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 20820715.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2982 + ... + 7108.

It is an arithmetic number, because the mean of its divisors is an integer number (3126960).

Almost surely, 2^20820715 is an apocalyptic number.

20820715 is a deficient number, since it is larger than the sum of its proper divisors (4194965).

20820715 is a wasteful number, since it uses less digits than its factorization.

20820715 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5141.

The product of its (nonzero) digits is 1120, while the sum is 25.

The square root of 20820715 is about 4562.9721673488. The cubic root of 20820715 is about 275.1050397634.

The spelling of 20820715 in words is "twenty million, eight hundred twenty thousand, seven hundred fifteen".