26691357778 has 16 divisors (see below), whose sum is σ = 40761947160. Its totient is φ = 13106209536.

The previous prime is 26691357767. The next prime is 26691357799. The reversal of 26691357778 is 87775319662.

It can be written as a sum of positive squares in 4 ways, for example, as 19956365289 + 6734992489 = 141267^2 + 82067^2 .

It is an unprimeable number.

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 7 ways as a sum of consecutive naturals, for example, 517125 + ... + 566392.

Almost surely, 2^26691357778 is an apocalyptic number.

26691357778 is a deficient number, since it is larger than the sum of its proper divisors (14070589382).

26691357778 is a wasteful number, since it uses less digits than its factorization.

26691357778 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1083741.

The product of its digits is 26671680, while the sum is 61.

The spelling of 26691357778 in words is "twenty-six billion, six hundred ninety-one million, three hundred fifty-seven thousand, seven hundred seventy-eight".