261499063506 has 8 divisors (see below), whose sum is σ = 522998127024. Its totient is φ = 87166354500.

The previous prime is 261499063459. The next prime is 261499063519. The reversal of 261499063506 is 605360994162.

261499063506 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a sphenic number, since it is the product of 3 distinct primes.

261499063506 is an admirable number.

It is a Smith number, since the sum of its digits (51) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

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 3 ways as a sum of consecutive naturals, for example, 21791588620 + ... + 21791588631.

It is an arithmetic number, because the mean of its divisors is an integer number (65374765878).

Almost surely, 2^261499063506 is an apocalyptic number.

261499063506 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

261499063506 is a wasteful number, since it uses less digits than its factorization.

261499063506 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 43583177256.

The product of its (nonzero) digits is 2099520, while the sum is 51.

The spelling of 261499063506 in words is "two hundred sixty-one billion, four hundred ninety-nine million, sixty-three thousand, five hundred six".