27109402075561 has 27 divisors (see below), whose sum is σ = 29668086983151. Its totient is φ = 24760085336064.

The previous prime is 27109402075517. The next prime is 27109402075589. The reversal of 27109402075561 is 16557020490172.

It is a happy number.

The square root of 27109402075561 is 5206669.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in 13 ways, for example, as 23056025185561 + 4053376890000 = 4801669^2 + 2013300^2 .

It is not a de Polignac number, because 27109402075561 - 2²³ = 27109393686953 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (27109402975561) by changing a digit.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 6565607545 + ... + 6565611673.

It is an arithmetic number, because the mean of its divisors is an integer number (1098818036413).

Almost surely, 2^{27109402075561} is an apocalyptic number.

27109402075561 is the 5206669-th square number.

27109402075561 is the 2603335-th centered octagonal number.

It is an amenable number.

27109402075561 is a deficient number, since it is larger than the sum of its proper divisors (2558684907590).

27109402075561 is an frugal number, since it uses more digits than its factorization.

27109402075561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8478 (or 4239 counting only the distinct ones).

The product of its (nonzero) digits is 1058400, while the sum is 49.

The spelling of 27109402075561 in words is "twenty-seven trillion, one hundred nine billion, four hundred two million, seventy-five thousand, five hundred sixty-one".