261438077660 has 24 divisors (see below), whose sum is σ = 549186421056. Its totient is φ = 104543524800.

The previous prime is 261438077629. The next prime is 261438077669. The reversal of 261438077660 is 66770834162.

It is a junction number, because it is equal to n+sod(n) for n = 261438077599 and 261438077608.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261438077669) 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, 1913972 + ... + 2046011.

It is an arithmetic number, because the mean of its divisors is an integer number (22882767544).

Almost surely, 2^261438077660 is an apocalyptic number.

261438077660 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

261438077660 is an abundant number, since it is smaller than the sum of its proper divisors (287748343396).

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

261438077660 is a wasteful number, since it uses less digits than its factorization.

261438077660 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3963293 (or 3963291 counting only the distinct ones).

The product of its (nonzero) digits is 2032128, while the sum is 50.

The spelling of 261438077660 in words is "two hundred sixty-one billion, four hundred thirty-eight million, seventy-seven thousand, six hundred sixty".