15561407 has 2 divisors, whose sum is σ = 15561408. Its totient is φ = 15561406.

The previous prime is 15561391. The next prime is 15561431. The reversal of 15561407 is 70416551.

It is a weak prime.

It is an emirp because it is prime and its reverse (70416551) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 15561407 - 2⁴ = 15561391 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 15561407.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (15561457) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 7780703 + 7780704.

It is an arithmetic number, because the mean of its divisors is an integer number (7780704).

Almost surely, 2^15561407 is an apocalyptic number.

15561407 is a deficient number, since it is larger than the sum of its proper divisors (1).

15561407 is an equidigital number, since it uses as much as digits as its factorization.

15561407 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 4200, while the sum is 29.

The square root of 15561407 is about 3944.7949249612. The cubic root of 15561407 is about 249.6603761649.

Adding to 15561407 its reverse (70416551), we get a palindrome (85977958).

The spelling of 15561407 in words is "fifteen million, five hundred sixty-one thousand, four hundred seven".