820715 has 16 divisors (see below), whose sum is σ = 1140480. Its totient is φ = 555360.

The previous prime is 820711. The next prime is 820723. The reversal of 820715 is 517028.

It is not a de Polignac number, because 820715 - 2² = 820711 is a prime.

It is a super-2 number, since 2×820715² = 1347146222450, which contains 22 as substring.

It is a nialpdrome in base 7.

It is not an unprimeable number, because it can be changed into a prime (820711) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 4496 + ... + 4674.

It is an arithmetic number, because the mean of its divisors is an integer number (71280).

2⁸²⁰⁷¹⁵ is an apocalyptic number.

820715 is a deficient number, since it is larger than the sum of its proper divisors (319765).

820715 is a wasteful number, since it uses less digits than its factorization.

820715 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 322.

The product of its (nonzero) digits is 560, while the sum is 23.

The square root of 820715 is about 905.9332204970. The cubic root of 820715 is about 93.6262129203.

The spelling of 820715 in words is "eight hundred twenty thousand, seven hundred fifteen".