816220531 has 4 divisors (see below), whose sum is σ = 932823472. Its totient is φ = 699617592.

The previous prime is 816220501. The next prime is 816220547. The reversal of 816220531 is 135022618.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 816220531 - 2¹⁵ = 816187763 is a prime.

It is a super-2 number, since 2×816220531² = 1332431910451843922, 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 816220531.

It is not an unprimeable number, because it can be changed into a prime (816220501) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 58301460 + ... + 58301473.

It is an arithmetic number, because the mean of its divisors is an integer number (233205868).

Almost surely, 2^816220531 is an apocalyptic number.

816220531 is a deficient number, since it is larger than the sum of its proper divisors (116602941).

816220531 is a wasteful number, since it uses less digits than its factorization.

816220531 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 116602940.

The product of its (nonzero) digits is 2880, while the sum is 28.

The square root of 816220531 is about 28569.5735179929. The cubic root of 816220531 is about 934.5499205499.

The spelling of 816220531 in words is "eight hundred sixteen million, two hundred twenty thousand, five hundred thirty-one".