991403225020 has 48 divisors (see below), whose sum is σ = 2275560691488. Its totient is φ = 360593038080.

The previous prime is 991403225003. The next prime is 991403225041. The reversal of 991403225020 is 20522304199.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 28438471 + ... + 28473310.

It is an arithmetic number, because the mean of its divisors is an integer number (47407514406).

Almost surely, 2^991403225020 is an apocalyptic number.

It is an amenable number.

991403225020 is an abundant number, since it is smaller than the sum of its proper divisors (1284157466468).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

991403225020 is a wasteful number, since it uses less digits than its factorization.

991403225020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 56911870 (or 56911868 counting only the distinct ones).

The product of its (nonzero) digits is 38880, while the sum is 37.

The spelling of 991403225020 in words is "nine hundred ninety-one billion, four hundred three million, two hundred twenty-five thousand, twenty".