991908434916 has 243 divisors, whose sum is σ = 3051969225123. Its totient is φ = 270817636320.

The previous prime is 991908434887. The next prime is 991908434941. The reversal of 991908434916 is 619434809199.

The square root of 991908434916 is 995946.

It is a perfect power (a square), and thus also a powerful number.

991908434916 is a `hidden beast` number, since 9 + 9 + 190 + 8 + 434 + 9 + 1 + 6 = 666.

It is a Harshad number since it is a multiple of its sum of digits (63).

It is an unprimeable number.

It is a polite number, since it can be written in 80 ways as a sum of consecutive naturals, for example, 962083321 + ... + 962084351.

Almost surely, 2^991908434916 is an apocalyptic number.

991908434916 is the 995946-th square number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 991908434916

991908434916 is an abundant number, since it is smaller than the sum of its proper divisors (2060060790207).

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

991908434916 is a wasteful number, since it uses less digits than its factorization.

991908434916 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2132 (or 1066 counting only the distinct ones).

The product of its (nonzero) digits is 15116544, while the sum is 63.

The spelling of 991908434916 in words is "nine hundred ninety-one billion, nine hundred eight million, four hundred thirty-four thousand, nine hundred sixteen".