1561406 has 16 divisors (see below), whose sum is σ = 2920320. Its totient is φ = 608280.

The previous prime is 1561393. The next prime is 1561421. The reversal of 1561406 is 6041651.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4916 + ... + 5223.

It is an arithmetic number, because the mean of its divisors is an integer number (182520).

2^1561406 is an apocalyptic number.

1561406 is a deficient number, since it is larger than the sum of its proper divisors (1358914).

1561406 is a wasteful number, since it uses less digits than its factorization.

1561406 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10159.

The product of its (nonzero) digits is 720, while the sum is 23.

The square root of 1561406 is about 1249.5623233757. The cubic root of 1561406 is about 116.0126323936.

The spelling of 1561406 in words is "one million, five hundred sixty-one thousand, four hundred six".