261551107678337 has 4 divisors (see below), whose sum is σ = 262865434852800. Its totient is φ = 260236780503876.

The previous prime is 261551107678331. The next prime is 261551107678361. The reversal of 261551107678337 is 733876701155162.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 261551107678337 - 2¹⁰ = 261551107677313 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 261551107678337.

It is not an unprimeable number, because it can be changed into a prime (261551107678331) 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, 657163586933 + ... + 657163587330.

It is an arithmetic number, because the mean of its divisors is an integer number (65716358713200).

Almost surely, 2^{261551107678337} is an apocalyptic number.

It is an amenable number.

261551107678337 is a deficient number, since it is larger than the sum of its proper divisors (1314327174463).

261551107678337 is a wasteful number, since it uses less digits than its factorization.

261551107678337 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1314327174462.

The product of its (nonzero) digits is 44452800, while the sum is 62.

The spelling of 261551107678337 in words is "two hundred sixty-one trillion, five hundred fifty-one billion, one hundred seven million, six hundred seventy-eight thousand, three hundred thirty-seven".