646391071854 has 36 divisors (see below), whose sum is σ = 1539407943528. Its totient is φ = 195876081720.

The previous prime is 646391071817. The next prime is 646391071867. The reversal of 646391071854 is 458170193646.

It is a self number, because there is not a number n which added to its sum of digits gives 646391071854.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 148388794 + ... + 148393149.

Almost surely, 2^646391071854 is an apocalyptic number.

646391071854 is an abundant number, since it is smaller than the sum of its proper divisors (893016871674).

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

646391071854 is a wasteful number, since it uses less digits than its factorization.

646391071854 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 296781973 (or 296781959 counting only the distinct ones).

The product of its (nonzero) digits is 4354560, while the sum is 54.

The spelling of 646391071854 in words is "six hundred forty-six billion, three hundred ninety-one million, seventy-one thousand, eight hundred fifty-four".