261161263453 has 4 divisors (see below), whose sum is σ = 261344022940. Its totient is φ = 260978503968.

The previous prime is 261161263411. The next prime is 261161263481. The reversal of 261161263453 is 354362161162.

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

It can be written as a sum of positive squares in 2 ways, for example, as 43148844729 + 218012418724 = 207723^2 + 466918^2 .

It is a cyclic number.

It is not a de Polignac number, because 261161263453 - 2²⁵ = 261127709021 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261161261453) 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, 91377600 + ... + 91380457.

It is an arithmetic number, because the mean of its divisors is an integer number (65336005735).

Almost surely, 2^261161263453 is an apocalyptic number.

It is an amenable number.

261161263453 is a deficient number, since it is larger than the sum of its proper divisors (182759487).

261161263453 is a wasteful number, since it uses less digits than its factorization.

261161263453 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 182759486.

The product of its digits is 155520, while the sum is 40.

The spelling of 261161263453 in words is "two hundred sixty-one billion, one hundred sixty-one million, two hundred sixty-three thousand, four hundred fifty-three".