161771785025 has 12 divisors (see below), whose sum is σ = 211154751600. Its totient is φ = 122605984080.

The previous prime is 161771785009. The next prime is 161771785037. The reversal of 161771785025 is 520587177161.

It is not a de Polignac number, because 161771785025 - 2⁴ = 161771785009 is a prime.

It is a super-2 number, since 2×161771785025² (a number of 23 digits) contains 22 as substring.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 170285615 + ... + 170286564.

It is an arithmetic number, because the mean of its divisors is an integer number (17596229300).

Almost surely, 2^161771785025 is an apocalyptic number.

It is an amenable number.

161771785025 is a deficient number, since it is larger than the sum of its proper divisors (49382966575).

161771785025 is a wasteful number, since it uses less digits than its factorization.

161771785025 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 340572208 (or 340572203 counting only the distinct ones).

The product of its (nonzero) digits is 823200, while the sum is 50.

The spelling of 161771785025 in words is "one hundred sixty-one billion, seven hundred seventy-one million, seven hundred eighty-five thousand, twenty-five".