261665011652 has 24 divisors (see below), whose sum is σ = 499754973312. Its totient is φ = 118888004000.

The previous prime is 261665011639. The next prime is 261665011681. The reversal of 261665011652 is 256110566162.

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, 1161323 + ... + 1368210.

It is an arithmetic number, because the mean of its divisors is an integer number (20823123888).

Almost surely, 2^261665011652 is an apocalyptic number.

261665011652 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

It is an amenable number.

261665011652 is a deficient number, since it is larger than the sum of its proper divisors (238089961660).

261665011652 is a wasteful number, since it uses less digits than its factorization.

261665011652 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2531899 (or 2531897 counting only the distinct ones).

The product of its (nonzero) digits is 129600, while the sum is 41.

The spelling of 261665011652 in words is "two hundred sixty-one billion, six hundred sixty-five million, eleven thousand, six hundred fifty-two".