261421053317023 has 4 divisors (see below), whose sum is σ = 261633763695240. Its totient is φ = 261208342938808.

The previous prime is 261421053316991. The next prime is 261421053317051. The reversal of 261421053317023 is 320713350124162.

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 261421053317023 - 2⁵ = 261421053316991 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 (261421053317623) 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, 106355187265 + ... + 106355189722.

It is an arithmetic number, because the mean of its divisors is an integer number (65408440923810).

Almost surely, 2^{261421053317023} is an apocalyptic number.

261421053317023 is a deficient number, since it is larger than the sum of its proper divisors (212710378217).

261421053317023 is a wasteful number, since it uses less digits than its factorization.

261421053317023 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 212710378216.

The product of its (nonzero) digits is 181440, while the sum is 40.

The spelling of 261421053317023 in words is "two hundred sixty-one trillion, four hundred twenty-one billion, fifty-three million, three hundred seventeen thousand, twenty-three".