261962392221 has 32 divisors (see below), whose sum is σ = 405025125120. Its totient is φ = 167024100672.

The previous prime is 261962392189. The next prime is 261962392319. The reversal of 261962392221 is 122293269162.

261962392221 is a `hidden beast` number, since 2 + 6 + 19 + 623 + 9 + 2 + 2 + 2 + 1 = 666.

It is not a de Polignac number, because 261962392221 - 2⁵ = 261962392189 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261962392121) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 4849855 + ... + 4903571.

It is an arithmetic number, because the mean of its divisors is an integer number (12657035160).

Almost surely, 2^261962392221 is an apocalyptic number.

It is an amenable number.

261962392221 is a deficient number, since it is larger than the sum of its proper divisors (143062732899).

261962392221 is a wasteful number, since it uses less digits than its factorization.

261962392221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 61602 (or 61596 counting only the distinct ones).

The product of its digits is 279936, while the sum is 45.

The spelling of 261962392221 in words is "two hundred sixty-one billion, nine hundred sixty-two million, three hundred ninety-two thousand, two hundred twenty-one".