26405400561 has 4 divisors (see below), whose sum is σ = 35207200752. Its totient is φ = 17603600372.

The previous prime is 26405400547. The next prime is 26405400563. The reversal of 26405400561 is 16500450462.

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 26405400561 - 2¹³ = 26405392369 is a prime.

It is a super-2 number, since 2×26405400561² (a number of 22 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (26405400563) 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, 4400900091 + ... + 4400900096.

It is an arithmetic number, because the mean of its divisors is an integer number (8801800188).

Almost surely, 2^26405400561 is an apocalyptic number.

It is an amenable number.

26405400561 is a deficient number, since it is larger than the sum of its proper divisors (8801800191).

26405400561 is an equidigital number, since it uses as much as digits as its factorization.

26405400561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8801800190.

The product of its (nonzero) digits is 28800, while the sum is 33.

The spelling of 26405400561 in words is "twenty-six billion, four hundred five million, four hundred thousand, five hundred sixty-one".