26691234557 has 24 divisors (see below), whose sum is σ = 31862414976. Its totient is φ = 22180485888.

The previous prime is 26691234553. The next prime is 26691234587. The reversal of 26691234557 is 75543219662.

It is not a de Polignac number, because 26691234557 - 2² = 26691234553 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (26691234553) 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, 68033 + ... + 240854.

It is an arithmetic number, because the mean of its divisors is an integer number (1327600624).

Almost surely, 2^26691234557 is an apocalyptic number.

It is an amenable number.

26691234557 is a deficient number, since it is larger than the sum of its proper divisors (5171180419).

26691234557 is a wasteful number, since it uses less digits than its factorization.

26691234557 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 308957 (or 308940 counting only the distinct ones).

The product of its digits is 2721600, while the sum is 50.

The spelling of 26691234557 in words is "twenty-six billion, six hundred ninety-one million, two hundred thirty-four thousand, five hundred fifty-seven".