671539813 has 4 divisors (see below), whose sum is σ = 767474080. Its totient is φ = 575605548.

The previous prime is 671539793. The next prime is 671539823. The reversal of 671539813 is 318935176.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 671539813 - 2²¹ = 669442661 is a prime.

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 671539813.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (671539823) 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, 47967123 + ... + 47967136.

It is an arithmetic number, because the mean of its divisors is an integer number (191868520).

Almost surely, 2^671539813 is an apocalyptic number.

It is an amenable number.

671539813 is a deficient number, since it is larger than the sum of its proper divisors (95934267).

671539813 is an equidigital number, since it uses as much as digits as its factorization.

671539813 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 95934266.

The product of its digits is 136080, while the sum is 43.

The square root of 671539813 is about 25914.0852240630. The cubic root of 671539813 is about 875.7038420650.

The spelling of 671539813 in words is "six hundred seventy-one million, five hundred thirty-nine thousand, eight hundred thirteen".