991792377951 has 32 divisors (see below), whose sum is σ = 1390491214848. Its totient is φ = 627589712640.

The previous prime is 991792377949. The next prime is 991792378001. The reversal of 991792377951 is 159773297199.

It is not a de Polignac number, because 991792377951 - 2¹ = 991792377949 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (69).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (991792377931) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 26421286 + ... + 26458796.

It is an arithmetic number, because the mean of its divisors is an integer number (43452850464).

Almost surely, 2^991792377951 is an apocalyptic number.

991792377951 is a deficient number, since it is larger than the sum of its proper divisors (398698836897).

991792377951 is a wasteful number, since it uses less digits than its factorization.

991792377951 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 40471.

The product of its digits is 67512690, while the sum is 69.

The spelling of 991792377951 in words is "nine hundred ninety-one billion, seven hundred ninety-two million, three hundred seventy-seven thousand, nine hundred fifty-one".