1991000902 has 16 divisors (see below), whose sum is σ = 3313224000. Its totient is φ = 889660840.

The previous prime is 1991000863. The next prime is 1991000909. The reversal of 1991000902 is 2090001991.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1991000909) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 765652 + ... + 768247.

It is an arithmetic number, because the mean of its divisors is an integer number (207076500).

Almost surely, 2^1991000902 is an apocalyptic number.

1991000902 is a deficient number, since it is larger than the sum of its proper divisors (1322223098).

1991000902 is a wasteful number, since it uses less digits than its factorization.

1991000902 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1533971.

The product of its (nonzero) digits is 1458, while the sum is 31.

The square root of 1991000902 is about 44620.6331420790. The cubic root of 1991000902 is about 1258.0285163677.

The spelling of 1991000902 in words is "one billion, nine hundred ninety-one million, nine hundred two", and thus it is an aban number.