261147780634438 has 16 divisors (see below), whose sum is σ = 397451022232896. Its totient is φ = 128667379538880.

The previous prime is 261147780634421. The next prime is 261147780634441. The reversal of 261147780634438 is 834436087741162.

It is a self number, because there is not a number n which added to its sum of digits gives 261147780634438.

It is a congruent number.

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, 818085358 + ... + 818404513.

It is an arithmetic number, because the mean of its divisors is an integer number (24840688889556).

Almost surely, 2^{261147780634438} is an apocalyptic number.

261147780634438 is a deficient number, since it is larger than the sum of its proper divisors (136303241598458).

261147780634438 is a wasteful number, since it uses less digits than its factorization.

261147780634438 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1636491039.

The product of its (nonzero) digits is 130056192, while the sum is 64.

The spelling of 261147780634438 in words is "two hundred sixty-one trillion, one hundred forty-seven billion, seven hundred eighty million, six hundred thirty-four thousand, four hundred thirty-eight".