26691691623 has 4 divisors (see below), whose sum is σ = 35588922168. Its totient is φ = 17794461080.

The previous prime is 26691691597. The next prime is 26691691643. The reversal of 26691691623 is 32619619662.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 26691691623 - 2⁵ = 26691691591 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (26691691643) 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, 4448615268 + ... + 4448615273.

It is an arithmetic number, because the mean of its divisors is an integer number (8897230542).

Almost surely, 2^26691691623 is an apocalyptic number.

26691691623 is a deficient number, since it is larger than the sum of its proper divisors (8897230545).

26691691623 is an equidigital number, since it uses as much as digits as its factorization.

26691691623 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8897230544.

The product of its digits is 1259712, while the sum is 51.

The spelling of 26691691623 in words is "twenty-six billion, six hundred ninety-one million, six hundred ninety-one thousand, six hundred twenty-three".