195557643961 has 9 divisors (see below), whose sum is σ = 196837297839. Its totient is φ = 194286264336.

The previous prime is 195557643943. The next prime is 195557643977. The reversal of 195557643961 is 169346755591.

The square root of 195557643961 is 442219.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 192971311225 + 2586332736 = 439285^2 + 50856^2 .

It is not a de Polignac number, because 195557643961 - 2¹⁷ = 195557512889 is a prime.

It is a super-2 number, since 2×195557643961² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 195557643961.

It is not an unprimeable number, because it can be changed into a prime (195557643661) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 72080341 + ... + 72083053.

It is an arithmetic number, because the mean of its divisors is an integer number (21870810871).

Almost surely, 2^195557643961 is an apocalyptic number.

195557643961 is the 442219-th square number.

195557643961 is the 221110-th centered octagonal number.

It is an amenable number.

195557643961 is a deficient number, since it is larger than the sum of its proper divisors (1279653878).

195557643961 is an frugal number, since it uses more digits than its factorization.

195557643961 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5752 (or 2876 counting only the distinct ones).

The product of its digits is 30618000, while the sum is 61.

The spelling of 195557643961 in words is "one hundred ninety-five billion, five hundred fifty-seven million, six hundred forty-three thousand, nine hundred sixty-one".