261421167624145 has 16 divisors (see below), whose sum is σ = 314840114815248. Its totient is φ = 208380468890880.

The previous prime is 261421167624119. The next prime is 261421167624173. The reversal of 261421167624145 is 541426761124162.

It can be written as a sum of positive squares in 8 ways, for example, as 170267423406336 + 91153744217809 = 13048656^2 + 9547447^2 .

It is not a de Polignac number, because 261421167624145 - 2⁹ = 261421167623633 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 261421167624092 and 261421167624101.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 225205167 + ... + 226363003.

It is an arithmetic number, because the mean of its divisors is an integer number (19677507175953).

Almost surely, 2^{261421167624145} is an apocalyptic number.

It is an amenable number.

261421167624145 is a deficient number, since it is larger than the sum of its proper divisors (53418947191103).

261421167624145 is a wasteful number, since it uses less digits than its factorization.

261421167624145 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1321140.

The product of its digits is 3870720, while the sum is 52.

The spelling of 261421167624145 in words is "two hundred sixty-one trillion, four hundred twenty-one billion, one hundred sixty-seven million, six hundred twenty-four thousand, one hundred forty-five".