12401561 has 4 divisors (see below), whose sum is σ = 12665472. Its totient is φ = 12137652.

The previous prime is 12401539. The next prime is 12401563. The reversal of 12401561 is 16510421.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 16510421 = 107 ⋅154303.

It is a cyclic number.

It is not a de Polignac number, because 12401561 - 2⁶ = 12401497 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (12401563) 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, 131885 + ... + 131978.

It is an arithmetic number, because the mean of its divisors is an integer number (3166368).

Almost surely, 2^12401561 is an apocalyptic number.

It is an amenable number.

12401561 is a deficient number, since it is larger than the sum of its proper divisors (263911).

12401561 is an equidigital number, since it uses as much as digits as its factorization.

12401561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 263910.

The product of its (nonzero) digits is 240, while the sum is 20.

The square root of 12401561 is about 3521.5850124624. The cubic root of 12401561 is about 231.4686176083.

Adding to 12401561 its reverse (16510421), we get a palindrome (28911982).

The spelling of 12401561 in words is "twelve million, four hundred one thousand, five hundred sixty-one".