391990267986 has 16 divisors (see below), whose sum is σ = 830097038304. Its totient is φ = 122977338944.

The previous prime is 391990267931. The next prime is 391990268017. The reversal of 391990267986 is 689762099193.

It is a self number, because there is not a number n which added to its sum of digits gives 391990267986.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1921520820 + ... + 1921521023.

It is an arithmetic number, because the mean of its divisors is an integer number (51881064894).

Almost surely, 2^391990267986 is an apocalyptic number.

391990267986 is an abundant number, since it is smaller than the sum of its proper divisors (438106770318).

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

391990267986 is a wasteful number, since it uses less digits than its factorization.

391990267986 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3843041865.

The product of its (nonzero) digits is 79361856, while the sum is 69.

The spelling of 391990267986 in words is "three hundred ninety-one billion, nine hundred ninety million, two hundred sixty-seven thousand, nine hundred eighty-six".