261555612923 has 8 divisors (see below), whose sum is σ = 287386155840. Its totient is φ = 236067196680.

The previous prime is 261555612907. The next prime is 261555612991. The reversal of 261555612923 is 329216555162.

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 261555612923 - 2⁴ = 261555612907 is a prime.

It is a super-2 number, since 2×261555612923² (a number of 24 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (261555612223) 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, 85530065 + ... + 85533122.

It is an arithmetic number, because the mean of its divisors is an integer number (35923269480).

Almost surely, 2^261555612923 is an apocalyptic number.

261555612923 is a deficient number, since it is larger than the sum of its proper divisors (25830542917).

261555612923 is a wasteful number, since it uses less digits than its factorization.

261555612923 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 171063337.

The product of its digits is 972000, while the sum is 47.

It can be divided in two parts, 261555 and 612923, that added together give a palindrome (874478).

The spelling of 261555612923 in words is "two hundred sixty-one billion, five hundred fifty-five million, six hundred twelve thousand, nine hundred twenty-three".