901891900991 has 8 divisors (see below), whose sum is σ = 964923174000. Its totient is φ = 840416955840.

The previous prime is 901891900951. The next prime is 901891901017. The reversal of 901891900991 is 199009198109.

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

It is a de Polignac number, because none of the positive numbers 2^k-901891900991 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (901891900951) 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, 389080766 + ... + 389083083.

It is an arithmetic number, because the mean of its divisors is an integer number (120615396750).

Almost surely, 2^901891900991 is an apocalyptic number.

901891900991 is a deficient number, since it is larger than the sum of its proper divisors (63031273009).

901891900991 is a wasteful number, since it uses less digits than its factorization.

901891900991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 778163929.

The product of its (nonzero) digits is 472392, while the sum is 56.

The spelling of 901891900991 in words is "nine hundred one billion, eight hundred ninety-one million, nine hundred thousand, nine hundred ninety-one".