15625440409 has 2 divisors, whose sum is σ = 15625440410. Its totient is φ = 15625440408.

The previous prime is 15625440359. The next prime is 15625440433. The reversal of 15625440409 is 90404452651.

15625440409 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 10715355225 + 4910085184 = 103515^2 + 70072^2 .

It is a cyclic number.

It is not a de Polignac number, because 15625440409 - 2¹³ = 15625432217 is a prime.

It is not a weakly prime, because it can be changed into another prime (15625440109) 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, 7812720204 + 7812720205.

It is an arithmetic number, because the mean of its divisors is an integer number (7812720205).

Almost surely, 2^15625440409 is an apocalyptic number.

It is an amenable number.

15625440409 is a deficient number, since it is larger than the sum of its proper divisors (1).

15625440409 is an equidigital number, since it uses as much as digits as its factorization.

15625440409 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 172800, while the sum is 40.

The spelling of 15625440409 in words is "fifteen billion, six hundred twenty-five million, four hundred forty thousand, four hundred nine".