991001451 has 32 divisors (see below), whose sum is σ = 1567531008. Its totient is φ = 549987840.

The previous prime is 991001443. The next prime is 991001461. The reversal of 991001451 is 154100199.

It is not a de Polignac number, because 991001451 - 2³ = 991001443 is a prime.

It is not an unprimeable number, because it can be changed into a prime (991001441) 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, 3115 + ... + 44628.

It is an arithmetic number, because the mean of its divisors is an integer number (48985344).

Almost surely, 2^991001451 is an apocalyptic number.

991001451 is a deficient number, since it is larger than the sum of its proper divisors (576529557).

991001451 is a wasteful number, since it uses less digits than its factorization.

991001451 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 47811.

The product of its (nonzero) digits is 1620, while the sum is 30.

The square root of 991001451 is about 31480.1755236530. The cubic root of 991001451 is about 996.9914413186.

The spelling of 991001451 in words is "nine hundred ninety-one million, one thousand, four hundred fifty-one".