161191947 has 24 divisors (see below), whose sum is σ = 254415616. Its totient is φ = 88923744.

The previous prime is 161191937. The next prime is 161192023. The reversal of 161191947 is 749191161.

It is not a de Polignac number, because 161191947 - 2⁸ = 161191691 is a prime.

It is not an unprimeable number, because it can be changed into a prime (161191937) by changing a digit.

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, 13098 + ... + 22224.

Almost surely, 2^161191947 is an apocalyptic number.

161191947 is a deficient number, since it is larger than the sum of its proper divisors (93223669).

161191947 is an equidigital number, since it uses as much as digits as its factorization.

161191947 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9195 (or 9166 counting only the distinct ones).

The product of its digits is 13608, while the sum is 39.

The square root of 161191947 is about 12696.1390587848. The cubic root of 161191947 is about 544.2282902768.

The spelling of 161191947 in words is "one hundred sixty-one million, one hundred ninety-one thousand, nine hundred forty-seven".