261729797989 has 16 divisors (see below), whose sum is σ = 292212354240. Its totient is φ = 232413442560.

The previous prime is 261729797971. The next prime is 261729798023. The reversal of 261729797989 is 989797927162.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-261729797989 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261729797929) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1182444 + ... + 1386229.

It is an arithmetic number, because the mean of its divisors is an integer number (18263272140).

Almost surely, 2^261729797989 is an apocalyptic number.

It is an amenable number.

261729797989 is a deficient number, since it is larger than the sum of its proper divisors (30482556251).

261729797989 is a wasteful number, since it uses less digits than its factorization.

261729797989 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2568900.

The product of its digits is 432081216, while the sum is 76.

The spelling of 261729797989 in words is "two hundred sixty-one billion, seven hundred twenty-nine million, seven hundred ninety-seven thousand, nine hundred eighty-nine".