27666313956721 has 4 divisors (see below), whose sum is σ = 30181433407344. Its totient is φ = 25151194506100.

The previous prime is 27666313956653. The next prime is 27666313956763. The reversal of 27666313956721 is 12765931366672.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 27666313956721 - 2⁹ = 27666313956209 is a prime.

It is a super-2 number, since 2×27666313956721² (a number of 28 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (27666313926721) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1257559725295 + ... + 1257559725316.

It is an arithmetic number, because the mean of its divisors is an integer number (7545358351836).

Almost surely, 2^{27666313956721} is an apocalyptic number.

It is an amenable number.

27666313956721 is a deficient number, since it is larger than the sum of its proper divisors (2515119450623).

27666313956721 is a wasteful number, since it uses less digits than its factorization.

27666313956721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2515119450622.

The product of its digits is 102876480, while the sum is 64.

The spelling of 27666313956721 in words is "twenty-seven trillion, six hundred sixty-six billion, three hundred thirteen million, nine hundred fifty-six thousand, seven hundred twenty-one".