27251657661 has 16 divisors (see below), whose sum is σ = 37618999808. Its totient is φ = 17529523200.

The previous prime is 27251657659. The next prime is 27251657701. The reversal of 27251657661 is 16675615272.

It is not a de Polignac number, because 27251657661 - 2¹ = 27251657659 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 27251657661.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (27251657621) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 403420 + ... + 466101.

It is an arithmetic number, because the mean of its divisors is an integer number (2351187488).

Almost surely, 2^27251657661 is an apocalyptic number.

It is an amenable number.

27251657661 is a deficient number, since it is larger than the sum of its proper divisors (10367342147).

27251657661 is a wasteful number, since it uses less digits than its factorization.

27251657661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 869892.

The product of its digits is 1058400, while the sum is 48.

The spelling of 27251657661 in words is "twenty-seven billion, two hundred fifty-one million, six hundred fifty-seven thousand, six hundred sixty-one".