261407770551291 has 128 divisors (see below), whose sum is σ = 453152914407424. Its totient is φ = 130322775260160.

The previous prime is 261407770551281. The next prime is 261407770551331. The reversal of 261407770551291 is 192155077704162.

It is not a de Polignac number, because 261407770551291 - 2⁹ = 261407770550779 is a prime.

It is not an unprimeable number, because it can be changed into a prime (261407770551271) by changing a digit.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 5354168706 + ... + 5354217528.

It is an arithmetic number, because the mean of its divisors is an integer number (3540257143808).

Almost surely, 2^{261407770551291} is an apocalyptic number.

261407770551291 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

261407770551291 is a deficient number, since it is larger than the sum of its proper divisors (191745143856133).

261407770551291 is a wasteful number, since it uses less digits than its factorization.

261407770551291 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 63633.

The product of its (nonzero) digits is 7408800, while the sum is 57.

The spelling of 261407770551291 in words is "two hundred sixty-one trillion, four hundred seven billion, seven hundred seventy million, five hundred fifty-one thousand, two hundred ninety-one".