991953002231 has 32 divisors (see below), whose sum is σ = 1098042264000. Its totient is φ = 892446170112.

The previous prime is 991953002219. The next prime is 991953002351. The reversal of 991953002231 is 132200359199.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-991953002231 is a prime.

It is a super-2 number, since 2×991953002231² (a number of 25 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (991953005231) 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, 8167805 + ... + 8288361.

It is an arithmetic number, because the mean of its divisors is an integer number (34313820750).

Almost surely, 2^991953002231 is an apocalyptic number.

991953002231 is a deficient number, since it is larger than the sum of its proper divisors (106089261769).

991953002231 is a wasteful number, since it uses less digits than its factorization.

991953002231 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 120851.

The product of its (nonzero) digits is 131220, while the sum is 44.

The spelling of 991953002231 in words is "nine hundred ninety-one billion, nine hundred fifty-three million, two thousand, two hundred thirty-one".