26781991977 has 32 divisors (see below), whose sum is σ = 39525727360. Its totient is φ = 16023536640.

The previous prime is 26781991969. The next prime is 26781992009. The reversal of 26781991977 is 77919918762.

It is a happy number.

It is not a de Polignac number, because 26781991977 - 2³ = 26781991969 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (26781911977) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 2098977 + ... + 2111697.

It is an arithmetic number, because the mean of its divisors is an integer number (1235178980).

Almost surely, 2^26781991977 is an apocalyptic number.

It is an amenable number.

26781991977 is a deficient number, since it is larger than the sum of its proper divisors (12743735383).

26781991977 is a wasteful number, since it uses less digits than its factorization.

26781991977 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14233.

The product of its digits is 24004512, while the sum is 66.

The spelling of 26781991977 in words is "twenty-six billion, seven hundred eighty-one million, nine hundred ninety-one thousand, nine hundred seventy-seven".