991133553431 has 8 divisors (see below), whose sum is σ = 1134397218720. Its totient is φ = 848288177568.

The previous prime is 991133553401. The next prime is 991133553463. The reversal of 991133553431 is 134355331199.

991133553431 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-991133553431 is a prime.

It is a super-2 number, since 2×991133553431² (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 (991133553401) 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, 104567276 + ... + 104576753.

It is an arithmetic number, because the mean of its divisors is an integer number (141799652340).

Almost surely, 2^991133553431 is an apocalyptic number.

991133553431 is a deficient number, since it is larger than the sum of its proper divisors (143263665289).

991133553431 is a wasteful number, since it uses less digits than its factorization.

991133553431 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 209144713.

The product of its digits is 656100, while the sum is 47.

The spelling of 991133553431 in words is "nine hundred ninety-one billion, one hundred thirty-three million, five hundred fifty-three thousand, four hundred thirty-one".