261772275664160 has 48 divisors (see below), whose sum is σ = 618495342873912. Its totient is φ = 104699032320000.

The previous prime is 261772275664153. The next prime is 261772275664199. The reversal of 261772275664160 is 61466572277162.

It can be written as a sum of positive squares in 4 ways, for example, as 252912151916944 + 8860123747216 = 15903212^2 + 2976596^2 .

It is a junction number, because it is equal to n+sod(n) for n = 261772275664093 and 261772275664102.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 75469991 + ... + 78862310.

Almost surely, 2^{261772275664160} is an apocalyptic number.

261772275664160 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

261772275664160 is an abundant number, since it is smaller than the sum of its proper divisors (356723067209752).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

261772275664160 is a wasteful number, since it uses less digits than its factorization.

261772275664160 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 154342917 (or 154342909 counting only the distinct ones).

The product of its (nonzero) digits is 71124480, while the sum is 62.

The spelling of 261772275664160 in words is "two hundred sixty-one trillion, seven hundred seventy-two billion, two hundred seventy-five million, six hundred sixty-four thousand, one hundred sixty".