26187456781 has 4 divisors (see below), whose sum is σ = 27565744000. Its totient is φ = 24809169564.

The previous prime is 26187456733. The next prime is 26187456787. The reversal of 26187456781 is 18765478162.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 26187456781 - 2⁷ = 26187456653 is a prime.

It is a super-2 number, since 2×26187456781² (a number of 22 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (26187456787) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 689143581 + ... + 689143618.

It is an arithmetic number, because the mean of its divisors is an integer number (6891436000).

Almost surely, 2^26187456781 is an apocalyptic number.

It is an amenable number.

26187456781 is a deficient number, since it is larger than the sum of its proper divisors (1378287219).

26187456781 is a wasteful number, since it uses less digits than its factorization.

26187456781 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1378287218.

The product of its digits is 4515840, while the sum is 55.

The spelling of 26187456781 in words is "twenty-six billion, one hundred eighty-seven million, four hundred fifty-six thousand, seven hundred eighty-one".