261311234445 has 48 divisors (see below), whose sum is σ = 484331460912. Its totient is φ = 129869260800.

The previous prime is 261311234417. The next prime is 261311234449. The reversal of 261311234445 is 544432113162.

261311234445 is a `hidden beast` number, since 2 + 61 + 31 + 123 + 4 + 445 = 666.

It can be written as a sum of positive squares in 8 ways, for example, as 21276889956 + 240034344489 = 145866^2 + 489933^2 .

It is not a de Polignac number, because 261311234445 - 2¹⁵ = 261311201677 is a prime.

It is a super-2 number, since 2×261311234445² (a number of 24 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261311234449) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 1613742 + ... + 1768271.

It is an arithmetic number, because the mean of its divisors is an integer number (10090238769).

Almost surely, 2^261311234445 is an apocalyptic number.

It is an amenable number.

261311234445 is a deficient number, since it is larger than the sum of its proper divisors (223020226467).

261311234445 is a wasteful number, since it uses less digits than its factorization.

261311234445 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3382142 (or 3382139 counting only the distinct ones).

The product of its digits is 69120, while the sum is 36.

The spelling of 261311234445 in words is "two hundred sixty-one billion, three hundred eleven million, two hundred thirty-four thousand, four hundred forty-five".