261487036285 has 4 divisors (see below), whose sum is σ = 313784443548. Its totient is φ = 209189629024.

The previous prime is 261487036249. The next prime is 261487036303. The reversal of 261487036285 is 582630784162.

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 110801771161 + 150685265124 = 332869^2 + 388182^2 .

It is a cyclic number.

It is not a de Polignac number, because 261487036285 - 2²⁹ = 260950165373 is a prime.

It is a super-2 number, since 2×261487036285² (a number of 24 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 26148703624 + ... + 26148703633.

It is an arithmetic number, because the mean of its divisors is an integer number (78446110887).

Almost surely, 2^261487036285 is an apocalyptic number.

It is an amenable number.

261487036285 is a deficient number, since it is larger than the sum of its proper divisors (52297407263).

261487036285 is an equidigital number, since it uses as much as digits as its factorization.

261487036285 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 52297407262.

The product of its (nonzero) digits is 3870720, while the sum is 52.

The spelling of 261487036285 in words is "two hundred sixty-one billion, four hundred eighty-seven million, thirty-six thousand, two hundred eighty-five".