261553772421043 has 16 divisors (see below), whose sum is σ = 273404534906880. Its totient is φ = 249743003042016.

The previous prime is 261553772420911. The next prime is 261553772421047. The reversal of 261553772421043 is 340124277355162.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-261553772421043 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (261553772421047) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 130194678 + ... + 132188356.

It is an arithmetic number, because the mean of its divisors is an integer number (17087783431680).

Almost surely, 2^{261553772421043} is an apocalyptic number.

261553772421043 is a gapful number since it is divisible by the number (23) formed by its first and last digit.

261553772421043 is a deficient number, since it is larger than the sum of its proper divisors (11850762485837).

261553772421043 is a wasteful number, since it uses less digits than its factorization.

261553772421043 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2003706.

The product of its (nonzero) digits is 8467200, while the sum is 52.

The spelling of 261553772421043 in words is "two hundred sixty-one trillion, five hundred fifty-three billion, seven hundred seventy-two million, four hundred twenty-one thousand, forty-three".