991629056391 has 8 divisors (see below), whose sum is σ = 1322197738224. Its totient is φ = 661073206080.

The previous prime is 991629056389. The next prime is 991629056393. The reversal of 991629056391 is 193650926199.

It is an interprime number because it is at equal distance from previous prime (991629056389) and next prime (991629056393).

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

It is not a de Polignac number, because 991629056391 - 2¹ = 991629056389 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (991629056393) 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, 3026086 + ... + 3337731.

It is an arithmetic number, because the mean of its divisors is an integer number (165274717278).

Almost surely, 2^991629056391 is an apocalyptic number.

991629056391 is a deficient number, since it is larger than the sum of its proper divisors (330568681833).

991629056391 is a wasteful number, since it uses less digits than its factorization.

991629056391 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6415761.

The product of its (nonzero) digits is 7085880, while the sum is 60.

The spelling of 991629056391 in words is "nine hundred ninety-one billion, six hundred twenty-nine million, fifty-six thousand, three hundred ninety-one".