261139034401 has 6 divisors (see below), whose sum is σ = 303773978850. Its totient is φ = 223833458016.

The previous prime is 261139034369. The next prime is 261139034459. The reversal of 261139034401 is 104430931162.

It can be written as a sum of positive squares in only one way, i.e., 249415342225 + 11723692176 = 499415^2 + 108276^2 .

It is not a de Polignac number, because 261139034401 - 2⁵ = 261139034369 is a prime.

It is a super-2 number, since 2×261139034401² (a number of 24 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (261139034501) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 2664683976 + ... + 2664684073.

It is an arithmetic number, because the mean of its divisors is an integer number (50628996475).

Almost surely, 2^261139034401 is an apocalyptic number.

It is an amenable number.

261139034401 is a deficient number, since it is larger than the sum of its proper divisors (42634944449).

261139034401 is an equidigital number, since it uses as much as digits as its factorization.

261139034401 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5329368063 (or 5329368056 counting only the distinct ones).

The product of its (nonzero) digits is 15552, while the sum is 34.

Adding to 261139034401 its reverse (104430931162), we get a palindrome (365569965563).

The spelling of 261139034401 in words is "two hundred sixty-one billion, one hundred thirty-nine million, thirty-four thousand, four hundred one".