261148594729 has 9 divisors (see below), whose sum is σ = 287053807831. Its totient is φ = 237402703120.

The previous prime is 261148594723. The next prime is 261148594769. The reversal of 261148594729 is 927495841162.

The square root of 261148594729 is 511027.

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., 219431349225 + 41717245504 = 468435^2 + 204248^2 .

It is not a de Polignac number, because 261148594729 - 2⁷ = 261148594601 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (261148594723) 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, 5598069 + ... + 5644525.

Almost surely, 2^261148594729 is an apocalyptic number.

261148594729 is the 511027-th square number.

261148594729 is the 255514-th centered octagonal number.

It is an amenable number.

261148594729 is a deficient number, since it is larger than the sum of its proper divisors (25905213102).

261148594729 is an frugal number, since it uses more digits than its factorization.

261148594729 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 92936 (or 46468 counting only the distinct ones).

The product of its digits is 8709120, while the sum is 58.

The spelling of 261148594729 in words is "two hundred sixty-one billion, one hundred forty-eight million, five hundred ninety-four thousand, seven hundred twenty-nine".