26157561 has 4 divisors (see below), whose sum is σ = 34876752. Its totient is φ = 17438372.

The previous prime is 26157553. The next prime is 26157569. The reversal of 26157561 is 16575162.

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 an interprime number because it is at equal distance from previous prime (26157553) and next prime (26157569).

It is a cyclic number.

It is not a de Polignac number, because 26157561 - 2³ = 26157553 is a prime.

It is not an unprimeable number, because it can be changed into a prime (26157569) 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, 4359591 + ... + 4359596.

It is an arithmetic number, because the mean of its divisors is an integer number (8719188).

Almost surely, 2^26157561 is an apocalyptic number.

It is an amenable number.

26157561 is a deficient number, since it is larger than the sum of its proper divisors (8719191).

26157561 is an equidigital number, since it uses as much as digits as its factorization.

26157561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8719190.

The product of its digits is 12600, while the sum is 33.

The square root of 26157561 is about 5114.4463043422. The cubic root of 26157561 is about 296.8468300658.

It can be divided in two parts, 261 and 57561, that multiplied together give a triangular number (15023421 = T₅₄₈₁).

The spelling of 26157561 in words is "twenty-six million, one hundred fifty-seven thousand, five hundred sixty-one".