261771512026 has 16 divisors (see below), whose sum is σ = 402166949184. Its totient is φ = 127721591424.

The previous prime is 261771512017. The next prime is 261771512039. The reversal of 261771512026 is 620215177162.

It is a self number, because there is not a number n which added to its sum of digits gives 261771512026.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1340311 + ... + 1523146.

It is an arithmetic number, because the mean of its divisors is an integer number (25135434324).

Almost surely, 2^261771512026 is an apocalyptic number.

261771512026 is a deficient number, since it is larger than the sum of its proper divisors (140395437158).

261771512026 is a wasteful number, since it uses less digits than its factorization.

261771512026 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2864565.

The product of its (nonzero) digits is 70560, while the sum is 40.

Adding to 261771512026 its reverse (620215177162), we get a palindrome (881986689188).

The spelling of 261771512026 in words is "two hundred sixty-one billion, seven hundred seventy-one million, five hundred twelve thousand, twenty-six".