261229931285 has 8 divisors (see below), whose sum is σ = 324285432120. Its totient is φ = 201777601984.

The previous prime is 261229931273. The next prime is 261229931317. The reversal of 261229931285 is 582139922162.

It can be written as a sum of positive squares in 4 ways, for example, as 402162916 + 260827768369 = 20054^2 + 510713^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 261229931285 - 2¹⁶ = 261229865749 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 900792722 + ... + 900793011.

It is an arithmetic number, because the mean of its divisors is an integer number (40535679015).

Almost surely, 2^261229931285 is an apocalyptic number.

It is an amenable number.

261229931285 is a deficient number, since it is larger than the sum of its proper divisors (63055500835).

261229931285 is a wasteful number, since it uses less digits than its factorization.

261229931285 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1801585767.

The product of its digits is 933120, while the sum is 50.

The spelling of 261229931285 in words is "two hundred sixty-one billion, two hundred twenty-nine million, nine hundred thirty-one thousand, two hundred eighty-five".