161557825199828 has 12 divisors (see below), whose sum is σ = 282727335874452. Its totient is φ = 80778586378560.

The previous prime is 161557825199801. The next prime is 161557825199861. The reversal of 161557825199828 is 828991528755161.

It can be written as a sum of positive squares in 2 ways, for example, as 48567685778704 + 112990139421124 = 6969052^2 + 10629682^2 .

It is a super-2 number, since 2×161557825199828² (a number of 29 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 80439353 + ... + 82423328.

It is an arithmetic number, because the mean of its divisors is an integer number (23560611322871).

Almost surely, 2^{161557825199828} is an apocalyptic number.

It is an amenable number.

161557825199828 is a deficient number, since it is larger than the sum of its proper divisors (121169510674624).

161557825199828 is a wasteful number, since it uses less digits than its factorization.

161557825199828 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 163110682 (or 163110680 counting only the distinct ones).

The product of its digits is 870912000, while the sum is 77.

The spelling of 161557825199828 in words is "one hundred sixty-one trillion, five hundred fifty-seven billion, eight hundred twenty-five million, one hundred ninety-nine thousand, eight hundred twenty-eight".