1561399 has 8 divisors (see below), whose sum is σ = 1889568. Its totient is φ = 1259520.

The previous prime is 1561393. The next prime is 1561421. The reversal of 1561399 is 9931651.

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

It is a cyclic number.

It is not a de Polignac number, because 1561399 - 2⁵ = 1561367 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1561393) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 6442 + ... + 6679.

It is an arithmetic number, because the mean of its divisors is an integer number (236196).

2^1561399 is an apocalyptic number.

1561399 is a deficient number, since it is larger than the sum of its proper divisors (328169).

1561399 is a wasteful number, since it uses less digits than its factorization.

1561399 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13145.

The product of its digits is 7290, while the sum is 34.

The square root of 1561399 is about 1249.5595223918. The cubic root of 1561399 is about 116.0124590264.

The spelling of 1561399 in words is "one million, five hundred sixty-one thousand, three hundred ninety-nine".