641672820837 has 20 divisors (see below), whose sum is σ = 959126972716. Its totient is φ = 427523624640.

The previous prime is 641672820821. The next prime is 641672820847. The reversal of 641672820837 is 738028276146.

641672820837 is a `hidden beast` number, since 6 + 416 + 72 + 82 + 0 + 83 + 7 = 666.

641672820837 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 2 ways, for example, as 421374949956 + 220297870881 = 649134^2 + 469359^2 .

It is not a de Polignac number, because 641672820837 - 2⁴ = 641672820821 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (641672820847) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 2256214 + ... + 2524647.

Almost surely, 2^641672820837 is an apocalyptic number.

It is an amenable number.

641672820837 is a deficient number, since it is larger than the sum of its proper divisors (317454151879).

641672820837 is a wasteful number, since it uses less digits than its factorization.

641672820837 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4782530 (or 4782521 counting only the distinct ones).

The product of its (nonzero) digits is 5419008, while the sum is 54.

The spelling of 641672820837 in words is "six hundred forty-one billion, six hundred seventy-two million, eight hundred twenty thousand, eight hundred thirty-seven".