991901902 has 8 divisors (see below), whose sum is σ = 1510059816. Its totient is φ = 488548632.

The previous prime is 991901899. The next prime is 991901951. The reversal of 991901902 is 209109199.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3700993 + ... + 3701260.

It is an arithmetic number, because the mean of its divisors is an integer number (188757477).

Almost surely, 2^991901902 is an apocalyptic number.

991901902 is a deficient number, since it is larger than the sum of its proper divisors (518157914).

991901902 is a wasteful number, since it uses less digits than its factorization.

991901902 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7402322.

The product of its (nonzero) digits is 13122, while the sum is 40.

The square root of 991901902 is about 31494.4741502378. The cubic root of 991901902 is about 997.2933144633.

The spelling of 991901902 in words is "nine hundred ninety-one million, nine hundred one thousand, nine hundred two".