261940779351 has 48 divisors (see below), whose sum is σ = 405634544640. Its totient is φ = 162458239680.

The previous prime is 261940779349. The next prime is 261940779407. The reversal of 261940779351 is 153977049162.

It is not a de Polignac number, because 261940779351 - 2¹ = 261940779349 is a prime.

It is a super-2 number, since 2×261940779351² (a number of 24 digits) contains 22 as substring.

It is a hoax number, since the sum of its digits (54) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261940779851) 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 47 ways as a sum of consecutive naturals, for example, 27805120 + ... + 27814538.

It is an arithmetic number, because the mean of its divisors is an integer number (8450719680).

Almost surely, 2^261940779351 is an apocalyptic number.

261940779351 is a deficient number, since it is larger than the sum of its proper divisors (143693765289).

261940779351 is a wasteful number, since it uses less digits than its factorization.

261940779351 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13116 (or 13113 counting only the distinct ones).

The product of its (nonzero) digits is 2857680, while the sum is 54.

The spelling of 261940779351 in words is "two hundred sixty-one billion, nine hundred forty million, seven hundred seventy-nine thousand, three hundred fifty-one".