991051431 has 48 divisors (see below), whose sum is σ = 1470815712. Its totient is φ = 591390720.

The previous prime is 991051429. The next prime is 991051459. The reversal of 991051431 is 134150199.

It is not a de Polignac number, because 991051431 - 2¹ = 991051429 is a prime.

It is a super-2 number, since 2×991051431² = 1964365877774295522, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 991051392 and 991051401.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (991056431) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 3577665 + ... + 3577941.

It is an arithmetic number, because the mean of its divisors is an integer number (30641994).

Almost surely, 2^991051431 is an apocalyptic number.

991051431 is a deficient number, since it is larger than the sum of its proper divisors (479764281).

991051431 is a wasteful number, since it uses less digits than its factorization.

991051431 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 432 (or 401 counting only the distinct ones).

The product of its (nonzero) digits is 4860, while the sum is 33.

The square root of 991051431 is about 31480.9693465751. The cubic root of 991051431 is about 997.0082017362.

The spelling of 991051431 in words is "nine hundred ninety-one million, fifty-one thousand, four hundred thirty-one".