391908002 has 4 divisors (see below), whose sum is σ = 587862006. Its totient is φ = 195954000.

The previous prime is 391907993. The next prime is 391908007. The reversal of 391908002 is 200809193.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 388444681 + 3463321 = 19709^2 + 1861^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 391908002.

It is not an unprimeable number, because it can be changed into a prime (391908007) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 97976999 + ... + 97977002.

Almost surely, 2^391908002 is an apocalyptic number.

391908002 is a deficient number, since it is larger than the sum of its proper divisors (195954004).

391908002 is a wasteful number, since it uses less digits than its factorization.

391908002 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 195954003.

The product of its (nonzero) digits is 3888, while the sum is 32.

The square root of 391908002 is about 19796.6664365494. Note that the first 3 decimals coincide. The cubic root of 391908002 is about 731.8038843267.

The spelling of 391908002 in words is "three hundred ninety-one million, nine hundred eight thousand, two".