261153734021 has 8 divisors (see below), whose sum is σ = 264112345440. Its totient is φ = 258204713968.

The previous prime is 261153733991. The next prime is 261153734033. The reversal of 261153734021 is 120437351162.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 261153734021 - 2³⁴ = 243973864837 is a prime.

It is a super-2 number, since 2×261153734021² (a number of 24 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261153734081) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2343071 + ... + 2451996.

It is an arithmetic number, because the mean of its divisors is an integer number (33014043180).

Almost surely, 2^261153734021 is an apocalyptic number.

It is an amenable number.

261153734021 is a deficient number, since it is larger than the sum of its proper divisors (2958611419).

261153734021 is a wasteful number, since it uses less digits than its factorization.

261153734021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4795683.

The product of its (nonzero) digits is 30240, while the sum is 35.

The spelling of 261153734021 in words is "two hundred sixty-one billion, one hundred fifty-three million, seven hundred thirty-four thousand, twenty-one".