1606406399 has 16 divisors (see below), whose sum is σ = 1748628000. Its totient is φ = 1466933376.

The previous prime is 1606406383. The next prime is 1606406419. The reversal of 1606406399 is 9936046061.

It is a Cunningham number, because it is equal to 40080²-1.

It is a cyclic number.

It is not a de Polignac number, because 1606406399 - 2⁴ = 1606406383 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 (1606406339) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 519512 + ... + 522594.

It is an arithmetic number, because the mean of its divisors is an integer number (109289250).

Almost surely, 2^1606406399 is an apocalyptic number.

1606406399 is a deficient number, since it is larger than the sum of its proper divisors (142221601).

1606406399 is a wasteful number, since it uses less digits than its factorization.

1606406399 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3514.

The product of its (nonzero) digits is 209952, while the sum is 44.

The square root of 1606406399 is about 40079.9999875250. Note that the first 4 decimals coincide. The cubic root of 1606406399 is about 1171.1660518053.

The spelling of 1606406399 in words is "one billion, six hundred six million, four hundred six thousand, three hundred ninety-nine".