261929855437471 has 4 divisors (see below), whose sum is σ = 282078305855752. Its totient is φ = 241781405019192.

The previous prime is 261929855437427. The next prime is 261929855437483. The reversal of 261929855437471 is 174734558929162.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-261929855437471 is a prime.

It is a super-3 number, since 3×261929855437471³ (a number of 44 digits) contains 333 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 261929855437394 and 261929855437403.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261929855437871) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 10074225209121 + ... + 10074225209146.

It is an arithmetic number, because the mean of its divisors is an integer number (70519576463938).

Almost surely, 2^{261929855437471} is an apocalyptic number.

261929855437471 is a deficient number, since it is larger than the sum of its proper divisors (20148450418281).

261929855437471 is a wasteful number, since it uses less digits than its factorization.

261929855437471 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20148450418280.

The product of its digits is 914457600, while the sum is 73.

The spelling of 261929855437471 in words is "two hundred sixty-one trillion, nine hundred twenty-nine billion, eight hundred fifty-five million, four hundred thirty-seven thousand, four hundred seventy-one".