26540256566 has 4 divisors (see below), whose sum is σ = 39810384852. Its totient is φ = 13270128282.

The previous prime is 26540256559. The next prime is 26540256583. The reversal of 26540256566 is 66565204562.

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

It is a super-2 number, since 2×26540256566² (a number of 22 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 26540256566.

It is a congruent number.

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 as a sum of consecutive naturals, namely, 6635064140 + ... + 6635064143.

It is an arithmetic number, because the mean of its divisors is an integer number (9952596213).

Almost surely, 2^26540256566 is an apocalyptic number.

26540256566 is a deficient number, since it is larger than the sum of its proper divisors (13270128286).

26540256566 is a wasteful number, since it uses less digits than its factorization.

26540256566 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13270128285.

The product of its (nonzero) digits is 2592000, while the sum is 47.

The spelling of 26540256566 in words is "twenty-six billion, five hundred forty million, two hundred fifty-six thousand, five hundred sixty-six".