195658153981 has 4 divisors (see below), whose sum is σ = 198865664764. Its totient is φ = 192450643200.

The previous prime is 195658153969. The next prime is 195658154093. The reversal of 195658153981 is 189351856591.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 63256777081 + 132401376900 = 251509^2 + 363870^2 .

It is a cyclic number.

It is not a de Polignac number, because 195658153981 - 2⁵ = 195658153949 is a prime.

It is a super-2 number, since 2×195658153981² (a number of 23 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (61), and also a Moran number because the ratio is a prime number: 3207510721 = 195658153981 / (1 + 9 + 5 + 6 + 5 + 8 + 1 + 5 + 3 + 9 + 8 + 1).

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (195658153921) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1603755300 + ... + 1603755421.

It is an arithmetic number, because the mean of its divisors is an integer number (49716416191).

Almost surely, 2^195658153981 is an apocalyptic number.

It is an amenable number.

195658153981 is a deficient number, since it is larger than the sum of its proper divisors (3207510783).

195658153981 is an equidigital number, since it uses as much as digits as its factorization.

195658153981 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3207510782.

The product of its digits is 11664000, while the sum is 61.

The spelling of 195658153981 in words is "one hundred ninety-five billion, six hundred fifty-eight million, one hundred fifty-three thousand, nine hundred eighty-one".