161257785 has 16 divisors (see below), whose sum is σ = 277859904. Its totient is φ = 79388352.

The previous prime is 161257781. The next prime is 161257793. The reversal of 161257785 is 587752161.

161257785 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 161257785 - 2² = 161257781 is a prime.

It is not an unprimeable number, because it can be changed into a prime (161257781) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 413287 + ... + 413676.

It is an arithmetic number, because the mean of its divisors is an integer number (17366244).

Almost surely, 2^161257785 is an apocalyptic number.

161257785 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

161257785 is a deficient number, since it is larger than the sum of its proper divisors (116602119).

161257785 is a wasteful number, since it uses less digits than its factorization.

161257785 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 826984.

The product of its digits is 117600, while the sum is 42.

The square root of 161257785 is about 12698.7316295762. The cubic root of 161257785 is about 544.3023759153.

The spelling of 161257785 in words is "one hundred sixty-one million, two hundred fifty-seven thousand, seven hundred eighty-five".