261497025583 has 4 divisors (see below), whose sum is σ = 261500525640. Its totient is φ = 261493525528.

The previous prime is 261497025571. The next prime is 261497025599. The reversal of 261497025583 is 385520794162.

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

It is a cyclic number.

It is not a de Polignac number, because 261497025583 - 2⁹ = 261497025071 is a prime.

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 261497025583.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261497025533) 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, 1635460 + ... + 1788217.

It is an arithmetic number, because the mean of its divisors is an integer number (65375131410).

It is a 1-persistent number, because it is pandigital, but 2⋅261497025583 = 522994051166 is not.

Almost surely, 2^261497025583 is an apocalyptic number.

261497025583 is a deficient number, since it is larger than the sum of its proper divisors (3500057).

261497025583 is an equidigital number, since it uses as much as digits as its factorization.

261497025583 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3500056.

The product of its (nonzero) digits is 3628800, while the sum is 52.

The spelling of 261497025583 in words is "two hundred sixty-one billion, four hundred ninety-seven million, twenty-five thousand, five hundred eighty-three".