991946856401 has 8 divisors (see below), whose sum is σ = 992359206144. Its totient is φ = 991534583440.

The previous prime is 991946856331. The next prime is 991946856403. The reversal of 991946856401 is 104658649199.

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

It is a cyclic number.

It is not a de Polignac number, because 991946856401 - 2²² = 991942662097 is a prime.

It is a super-2 number, since 2×991946856401² (a number of 25 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (991946856403) 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, 47173376 + ... + 47194398.

It is an arithmetic number, because the mean of its divisors is an integer number (124044900768).

Almost surely, 2^991946856401 is an apocalyptic number.

It is an amenable number.

991946856401 is a deficient number, since it is larger than the sum of its proper divisors (412349743).

991946856401 is a wasteful number, since it uses less digits than its factorization.

991946856401 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 38391.

The product of its (nonzero) digits is 16796160, while the sum is 62.

The spelling of 991946856401 in words is "nine hundred ninety-one billion, nine hundred forty-six million, eight hundred fifty-six thousand, four hundred one".