26991861264 has 45 divisors (see below), whose sum is σ = 75545240719. Its totient is φ = 8996629920.

The previous prime is 26991861227. The next prime is 26991861313. The reversal of 26991861264 is 46216819962.

The square root of 26991861264 is 164292.

It is a perfect power (a square), and thus also a powerful number.

26991861264 is a `hidden beast` number, since 2 + 6 + 9 + 9 + 18 + 612 + 6 + 4 = 666.

It is a Smith number, since the sum of its digits (54) coincides with the sum of the digits of its prime factors.

It is a nude number because it is divisible by every one of its digits.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 26991861264.

It is an unprimeable number.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 1964659 + ... + 1978349.

Almost surely, 2^26991861264 is an apocalyptic number.

26991861264 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

26991861264 is the 164292-nd square number.

It is an amenable number.

26991861264 is an abundant number, since it is smaller than the sum of its proper divisors (48553379455).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

26991861264 is an frugal number, since it uses more digits than its factorization.

26991861264 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 27396 (or 13696 counting only the distinct ones).

The product of its digits is 2239488, while the sum is 54.

The spelling of 26991861264 in words is "twenty-six billion, nine hundred ninety-one million, eight hundred sixty-one thousand, two hundred sixty-four".