27791397909 has 24 divisors (see below), whose sum is σ = 43799307552. Its totient is φ = 16840655520.

The previous prime is 27791397899. The next prime is 27791397919. The reversal of 27791397909 is 90979319772.

27791397909 is a `hidden beast` number, since 2 + 77 + 91 + 397 + 90 + 9 = 666.

It is an interprime number because it is at equal distance from previous prime (27791397899) and next prime (27791397919).

It is not a de Polignac number, because 27791397909 - 2⁹ = 27791397397 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (27791397919) 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, 759574 + ... + 795320.

It is an arithmetic number, because the mean of its divisors is an integer number (1824971148).

Almost surely, 2^27791397909 is an apocalyptic number.

It is an amenable number.

27791397909 is a deficient number, since it is larger than the sum of its proper divisors (16007909643).

27791397909 is a wasteful number, since it uses less digits than its factorization.

27791397909 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 43617 (or 43614 counting only the distinct ones).

The product of its (nonzero) digits is 13502538, while the sum is 63.

The spelling of 27791397909 in words is "twenty-seven billion, seven hundred ninety-one million, three hundred ninety-seven thousand, nine hundred nine".