261311445656100 has 324 divisors, whose sum is σ = 987935823935424. Its totient is φ = 56584733604480.

The previous prime is 261311445656089. The next prime is 261311445656153. The reversal of 261311445656100 is 1656544113162.

261311445656100 is a `hidden beast` number, since 2 + 6 + 1 + 31 + 1 + 4 + 4 + 56 + 561 + 0 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is an unprimeable number.

It is a polite number, since it can be written in 107 ways as a sum of consecutive naturals, for example, 55174464 + ... + 59723063.

It is an arithmetic number, because the mean of its divisors is an integer number (3049184641776).

Almost surely, 2^{261311445656100} is an apocalyptic number.

261311445656100 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

261311445656100 is an abundant number, since it is smaller than the sum of its proper divisors (726624378279324).

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

261311445656100 is a wasteful number, since it uses less digits than its factorization.

261311445656100 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 114897592 (or 114897563 counting only the distinct ones).

The product of its (nonzero) digits is 518400, while the sum is 45.

Adding to 261311445656100 its reverse (1656544113162), we get a palindrome (262967989769262).

The spelling of 261311445656100 in words is "two hundred sixty-one trillion, three hundred eleven billion, four hundred forty-five million, six hundred fifty-six thousand, one hundred".