3991577078628 has 72 divisors (see below), whose sum is σ = 10710249476472. Its totient is φ = 1249105093632.

The previous prime is 3991577078537. The next prime is 3991577078659. The reversal of 3991577078628 is 8268707751993.

3991577078628 is a `hidden beast` number, since 399 + 157 + 7 + 0 + 7 + 86 + 2 + 8 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 931568571684 + 3060008506944 = 965178^2 + 1749288^2 .

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 7971375 + ... + 8457302.

It is an arithmetic number, because the mean of its divisors is an integer number (148753464951).

Almost surely, 2^{3991577078628} is an apocalyptic number.

It is an amenable number.

3991577078628 is an abundant number, since it is smaller than the sum of its proper divisors (6718672397844).

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

3991577078628 is a wasteful number, since it uses less digits than its factorization.

3991577078628 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16429101 (or 16429096 counting only the distinct ones).

The product of its (nonzero) digits is 320060160, while the sum is 72.

The spelling of 3991577078628 in words is "three trillion, nine hundred ninety-one billion, five hundred seventy-seven million, seventy-eight thousand, six hundred twenty-eight".