820813431 has 16 divisors (see below), whose sum is σ = 1160953344. Its totient is φ = 514061184.

The previous prime is 820813429. The next prime is 820813451. The reversal of 820813431 is 134318028.

It is not a de Polignac number, because 820813431 - 2¹ = 820813429 is a prime.

It is a super-2 number, since 2×820813431² = 1347469377019983522, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (820813451) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 13186 + ... + 42608.

It is an arithmetic number, because the mean of its divisors is an integer number (72559584).

Almost surely, 2^820813431 is an apocalyptic number.

820813431 is a deficient number, since it is larger than the sum of its proper divisors (340139913).

820813431 is a wasteful number, since it uses less digits than its factorization.

820813431 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 29990.

The product of its (nonzero) digits is 4608, while the sum is 30.

The square root of 820813431 is about 28649.8417273115. The cubic root of 820813431 is about 936.2995573538.

The spelling of 820813431 in words is "eight hundred twenty million, eight hundred thirteen thousand, four hundred thirty-one".