646691321901 has 16 divisors (see below), whose sum is σ = 862882977600. Its totient is φ = 430813732608.

The previous prime is 646691321833. The next prime is 646691321957. The reversal of 646691321901 is 109123196646.

It is a happy number.

646691321901 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 646691321901 - 2⁹ = 646691321389 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (646691321401) 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, 25269330 + ... + 25294908.

It is an arithmetic number, because the mean of its divisors is an integer number (53930186100).

Almost surely, 2^646691321901 is an apocalyptic number.

It is an amenable number.

646691321901 is a deficient number, since it is larger than the sum of its proper divisors (216191655699).

646691321901 is a wasteful number, since it uses less digits than its factorization.

646691321901 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 31388.

The product of its (nonzero) digits is 419904, while the sum is 48.

The spelling of 646691321901 in words is "six hundred forty-six billion, six hundred ninety-one million, three hundred twenty-one thousand, nine hundred one".