991812460 has 24 divisors (see below), whose sum is σ = 2094852816. Its totient is φ = 394430400.

The previous prime is 991812449. The next prime is 991812461. The reversal of 991812460 is 64218199.

It is a super-2 number, since 2×991812460² = 1967383911622503200, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (991812461) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 139866 + ... + 146785.

It is an arithmetic number, because the mean of its divisors is an integer number (87285534).

Almost surely, 2^991812460 is an apocalyptic number.

It is an amenable number.

991812460 is an abundant number, since it is smaller than the sum of its proper divisors (1103040356).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

991812460 is a wasteful number, since it uses less digits than its factorization.

991812460 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 286833 (or 286831 counting only the distinct ones).

The product of its (nonzero) digits is 31104, while the sum is 40.

The square root of 991812460 is about 31493.0541548450. The cubic root of 991812460 is about 997.2633375103.

The spelling of 991812460 in words is "nine hundred ninety-one million, eight hundred twelve thousand, four hundred sixty".