820307971 has 6 divisors (see below), whose sum is σ = 954235860. Its totient is φ = 703121076.

The previous prime is 820307923. The next prime is 820308023. The reversal of 820307971 is 179703028.

It is not a de Polignac number, because 820307971 - 2²⁷ = 686090243 is a prime.

It is a super-2 number, since 2×820307971² = 1345810334572273682, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 820307971.

It is not an unprimeable number, because it can be changed into a prime (820307911) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 8370441 + ... + 8370538.

It is an arithmetic number, because the mean of its divisors is an integer number (159039310).

Almost surely, 2^820307971 is an apocalyptic number.

820307971 is a deficient number, since it is larger than the sum of its proper divisors (133927889).

820307971 is a wasteful number, since it uses less digits than its factorization.

820307971 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16740993 (or 16740986 counting only the distinct ones).

The product of its (nonzero) digits is 21168, while the sum is 37.

The square root of 820307971 is about 28641.0190286589. The cubic root of 820307971 is about 936.1073256257.

The spelling of 820307971 in words is "eight hundred twenty million, three hundred seven thousand, nine hundred seventy-one".