261553171244446 has 32 divisors (see below), whose sum is σ = 415593222448320. Its totient is φ = 123028964868096.

The previous prime is 261553171244423. The next prime is 261553171244459. The reversal of 261553171244446 is 644442171355162.

It is a super-2 number, since 2×261553171244446² (a number of 30 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (29) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1325852650 + ... + 1326049906.

It is an arithmetic number, because the mean of its divisors is an integer number (12987288201510).

Almost surely, 2^{261553171244446} is an apocalyptic number.

261553171244446 is a deficient number, since it is larger than the sum of its proper divisors (154040051203874).

261553171244446 is a wasteful number, since it uses less digits than its factorization.

261553171244446 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 214468.

The product of its digits is 19353600, while the sum is 55.

The spelling of 261553171244446 in words is "two hundred sixty-one trillion, five hundred fifty-three billion, one hundred seventy-one million, two hundred forty-four thousand, four hundred forty-six".