12261400538 has 8 divisors (see below), whose sum is σ = 18526350132. Its totient is φ = 6085950496.

The previous prime is 12261400537. The next prime is 12261400559. The reversal of 12261400538 is 83500416221.

It can be written as a sum of positive squares in 2 ways, for example, as 12233023609 + 28376929 = 110603^2 + 5327^2 .

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

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (12261400531) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 22374545 + ... + 22375092.

Almost surely, 2^12261400538 is an apocalyptic number.

12261400538 is a deficient number, since it is larger than the sum of its proper divisors (6264949594).

12261400538 is a wasteful number, since it uses less digits than its factorization.

12261400538 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 44749776.

The product of its (nonzero) digits is 11520, while the sum is 32.

Adding to 12261400538 its reverse (83500416221), we get a palindrome (95761816759).

The spelling of 12261400538 in words is "twelve billion, two hundred sixty-one million, four hundred thousand, five hundred thirty-eight".