27154515661 has 24 divisors (see below), whose sum is σ = 35190794520. Its totient is φ = 20744019072.

The previous prime is 27154515653. The next prime is 27154515683. The reversal of 27154515661 is 16651545172.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 5458993225 + 21695522436 = 73885^2 + 147294^2 .

It is not a de Polignac number, because 27154515661 - 2³ = 27154515653 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (27154515601) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 716506 + ... + 753451.

It is an arithmetic number, because the mean of its divisors is an integer number (1466283105).

Almost surely, 2^27154515661 is an apocalyptic number.

It is an amenable number.

27154515661 is a deficient number, since it is larger than the sum of its proper divisors (8036278859).

27154515661 is a wasteful number, since it uses less digits than its factorization.

27154515661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1470013 (or 1470006 counting only the distinct ones).

The product of its digits is 252000, while the sum is 43.

The spelling of 27154515661 in words is "twenty-seven billion, one hundred fifty-four million, five hundred fifteen thousand, six hundred sixty-one".