1399547561 has 4 divisors (see below), whose sum is σ = 1402872324. Its totient is φ = 1396222800.

The previous prime is 1399547519. The next prime is 1399547563. The reversal of 1399547561 is 1657459931.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 273273961 + 1126273600 = 16531^2 + 33560^2 .

It is a cyclic number.

It is not a de Polignac number, because 1399547561 - 2⁶ = 1399547497 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1399547563) 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 in 3 ways as a sum of consecutive naturals, for example, 1661750 + ... + 1662591.

It is an arithmetic number, because the mean of its divisors is an integer number (350718081).

Almost surely, 2^1399547561 is an apocalyptic number.

It is an amenable number.

1399547561 is a deficient number, since it is larger than the sum of its proper divisors (3324763).

1399547561 is an equidigital number, since it uses as much as digits as its factorization.

1399547561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3324762.

The product of its digits is 1020600, while the sum is 50.

The square root of 1399547561 is about 37410.5274087388. The cubic root of 1399547561 is about 1118.5684199292.

The spelling of 1399547561 in words is "one billion, three hundred ninety-nine million, five hundred forty-seven thousand, five hundred sixty-one".