646500001961 has 4 divisors (see below), whose sum is σ = 705272729424. Its totient is φ = 587727274500.

The previous prime is 646500001949. The next prime is 646500002021. The reversal of 646500001961 is 169100005646.

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 a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-646500001961 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (646500001921) 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, 29386363715 + ... + 29386363736.

It is an arithmetic number, because the mean of its divisors is an integer number (176318182356).

Almost surely, 2^646500001961 is an apocalyptic number.

It is an amenable number.

646500001961 is a deficient number, since it is larger than the sum of its proper divisors (58772727463).

646500001961 is a wasteful number, since it uses less digits than its factorization.

646500001961 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 58772727462.

The product of its (nonzero) digits is 38880, while the sum is 38.

The spelling of 646500001961 in words is "six hundred forty-six billion, five hundred million, one thousand, nine hundred sixty-one".