161640577 has 8 divisors (see below), whose sum is σ = 191102400. Its totient is φ = 133771344.

The previous prime is 161640529. The next prime is 161640587. The reversal of 161640577 is 775046161.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 161640577 - 2²⁷ = 27422849 is a prime.

It is a super-2 number, since 2×161640577² = 52255352265785858, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (161640587) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 397927 + ... + 398332.

It is an arithmetic number, because the mean of its divisors is an integer number (23887800).

Almost surely, 2^161640577 is an apocalyptic number.

It is an amenable number.

161640577 is a deficient number, since it is larger than the sum of its proper divisors (29461823).

161640577 is an equidigital number, since it uses as much as digits as its factorization.

161640577 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 796295.

The product of its (nonzero) digits is 35280, while the sum is 37.

The square root of 161640577 is about 12713.7947521580. The cubic root of 161640577 is about 544.7327219580.

The spelling of 161640577 in words is "one hundred sixty-one million, six hundred forty thousand, five hundred seventy-seven".