161140905 has 12 divisors (see below), whose sum is σ = 279310980. Its totient is φ = 85941792.

The previous prime is 161140891. The next prime is 161140933. The reversal of 161140905 is 509041161.

161140905 is a `hidden beast` number, since 1 + 611 + 40 + 9 + 0 + 5 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 64256256 + 96884649 = 8016^2 + 9843^2 .

It is not a de Polignac number, because 161140905 - 2¹⁷ = 161009833 is a prime.

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 11 ways as a sum of consecutive naturals, for example, 1790410 + ... + 1790499.

It is an arithmetic number, because the mean of its divisors is an integer number (23275915).

Almost surely, 2^161140905 is an apocalyptic number.

161140905 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

161140905 is a deficient number, since it is larger than the sum of its proper divisors (118170075).

161140905 is a wasteful number, since it uses less digits than its factorization.

161140905 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3580920 (or 3580917 counting only the distinct ones).

The product of its (nonzero) digits is 1080, while the sum is 27.

The square root of 161140905 is about 12694.1287609666. The cubic root of 161140905 is about 544.1708402749.

The spelling of 161140905 in words is "one hundred sixty-one million, one hundred forty thousand, nine hundred five".