261992657101 has 16 divisors (see below), whose sum is σ = 301029507328. Its totient is φ = 223360416000.

The previous prime is 261992657083. The next prime is 261992657111. The reversal of 261992657101 is 101756299162.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 261992657101 - 2⁷ = 261992656973 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261992657111) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1294051 + ... + 1482751.

It is an arithmetic number, because the mean of its divisors is an integer number (18814344208).

Almost surely, 2^261992657101 is an apocalyptic number.

It is an amenable number.

261992657101 is a deficient number, since it is larger than the sum of its proper divisors (39036850227).

261992657101 is a wasteful number, since it uses less digits than its factorization.

261992657101 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 189772.

The product of its (nonzero) digits is 408240, while the sum is 49.

The spelling of 261992657101 in words is "two hundred sixty-one billion, nine hundred ninety-two million, six hundred fifty-seven thousand, one hundred one".