991561410 has 48 divisors (see below), whose sum is σ = 2946355776. Its totient is φ = 226642464.

The previous prime is 991561399. The next prime is 991561421. The reversal of 991561410 is 14165199.

991561410 is a `hidden beast` number, since 9 + 91 + 561 + 4 + 1 + 0 = 666.

It is an interprime number because it is at equal distance from previous prime (991561399) and next prime (991561421).

It is a super-3 number, since 3×991561410³ (a number of 28 digits) contains 333 as substring.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 786324 + ... + 787583.

It is an arithmetic number, because the mean of its divisors is an integer number (61382412).

Almost surely, 2^991561410 is an apocalyptic number.

991561410 is a gapful number since it is divisible by the number (90) formed by its first and last digit.

991561410 is an abundant number, since it is smaller than the sum of its proper divisors (1954794366).

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

991561410 is a wasteful number, since it uses less digits than its factorization.

991561410 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1573927 (or 1573924 counting only the distinct ones).

The product of its (nonzero) digits is 9720, while the sum is 36.

The square root of 991561410 is about 31489.0681030735. The cubic root of 991561410 is about 997.1791871633.

The spelling of 991561410 in words is "nine hundred ninety-one million, five hundred sixty-one thousand, four hundred ten".