671321500812 has 18 divisors (see below), whose sum is σ = 1696951571588. Its totient is φ = 223773833592.

The previous prime is 671321500793. The next prime is 671321500813. The reversal of 671321500812 is 218005123176.

671321500812 is a `hidden beast` number, since 6 + 7 + 132 + 1 + 500 + 8 + 12 = 666.

It is a tau number, because it is divible by the number of its divisors (18).

It is a super-2 number, since 2×671321500812² (a number of 24 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (36), and also a Moran number because the ratio is a prime number: 18647819467 = 671321500812 / (6 + 7 + 1 + 3 + 2 + 1 + 5 + 0 + 0 + 8 + 1 + 2).

It is not an unprimeable number, because it can be changed into a prime (671321500813) 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, 9323909698 + ... + 9323909769.

Almost surely, 2^671321500812 is an apocalyptic number.

It is an amenable number.

671321500812 is an abundant number, since it is smaller than the sum of its proper divisors (1025630070776).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

671321500812 is a wasteful number, since it uses less digits than its factorization.

671321500812 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18647819477 (or 18647819472 counting only the distinct ones).

The product of its (nonzero) digits is 20160, while the sum is 36.

Adding to 671321500812 its reverse (218005123176), we get a palindrome (889326623988).

The spelling of 671321500812 in words is "six hundred seventy-one billion, three hundred twenty-one million, five hundred thousand, eight hundred twelve".