261356512650 has 24 divisors (see below), whose sum is σ = 648164151744. Its totient is φ = 69695070000.

The previous prime is 261356512633. The next prime is 261356512661. The reversal of 261356512650 is 56215653162.

It is a super-2 number, since 2×261356512650² (a number of 24 digits) contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 871188226 + ... + 871188525.

It is an arithmetic number, because the mean of its divisors is an integer number (27006839656).

Almost surely, 2^261356512650 is an apocalyptic number.

261356512650 is an abundant number, since it is smaller than the sum of its proper divisors (386807639094).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

261356512650 is a wasteful number, since it uses less digits than its factorization.

261356512650 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1742376766 (or 1742376761 counting only the distinct ones).

The product of its (nonzero) digits is 324000, while the sum is 42.

The spelling of 261356512650 in words is "two hundred sixty-one billion, three hundred fifty-six million, five hundred twelve thousand, six hundred fifty".