261562331274157 has 4 divisors (see below), whose sum is σ = 261641281573660. Its totient is φ = 261483380974656.

The previous prime is 261562331274151. The next prime is 261562331274241. The reversal of 261562331274157 is 751472133265162.

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 134509104013636 + 127053227260521 = 11597806^2 + 11271789^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-261562331274157 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 261562331274098 and 261562331274107.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261562331274151) 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, 39475144782 + ... + 39475151407.

It is an arithmetic number, because the mean of its divisors is an integer number (65410320393415).

Almost surely, 2^{261562331274157} is an apocalyptic number.

It is an amenable number.

261562331274157 is a deficient number, since it is larger than the sum of its proper divisors (78950299503).

261562331274157 is an equidigital number, since it uses as much as digits as its factorization.

261562331274157 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 78950299502.

The product of its digits is 12700800, while the sum is 55.

The spelling of 261562331274157 in words is "two hundred sixty-one trillion, five hundred sixty-two billion, three hundred thirty-one million, two hundred seventy-four thousand, one hundred fifty-seven".