391987577390 has 16 divisors (see below), whose sum is σ = 710313062400. Its totient is φ = 155742714720.

The previous prime is 391987577327. The next prime is 391987577407. The reversal of 391987577390 is 93775789193.

It is a self number, because there is not a number n which added to its sum of digits gives 391987577390.

It is a congruent number.

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, 131537966 + ... + 131540945.

It is an arithmetic number, because the mean of its divisors is an integer number (44394566400).

Almost surely, 2^391987577390 is an apocalyptic number.

391987577390 is a deficient number, since it is larger than the sum of its proper divisors (318325485010).

391987577390 is a wasteful number, since it uses less digits than its factorization.

391987577390 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 263079067.

The product of its (nonzero) digits is 90016920, while the sum is 68.

The spelling of 391987577390 in words is "three hundred ninety-one billion, nine hundred eighty-seven million, five hundred seventy-seven thousand, three hundred ninety".