1428613209 has 27 divisors (see below), whose sum is σ = 2119893087. Its totient is φ = 927084816.

The previous prime is 1428613201. The next prime is 1428613217. The reversal of 1428613209 is 9023168241.

The square root of 1428613209 is 37797.

It is a perfect power (a square), and thus also a powerful number.

1428613209 is a `hidden beast` number, since 14 + 2 + 8 + 613 + 20 + 9 = 666.

It is an interprime number because it is at equal distance from previous prime (1428613201) and next prime (1428613217).

It can be written as a sum of positive squares in only one way, i.e., 1351665225 + 76947984 = 36765^2 + 8772^2 .

It is not a de Polignac number, because 1428613209 - 2³ = 1428613201 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (1428613201) by changing a digit.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 4875667 + ... + 4875959.

Almost surely, 2^1428613209 is an apocalyptic number.

1428613209 is the 37797-th square number.

1428613209 is the 18899-th centered octagonal number.

It is an amenable number.

1428613209 is a deficient number, since it is larger than the sum of its proper divisors (691279878).

1428613209 is an frugal number, since it uses more digits than its factorization.

1428613209 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 678 (or 339 counting only the distinct ones).

The product of its (nonzero) digits is 20736, while the sum is 36.

The cubic root of 1428613209 is about 1126.2588598644.

Multiplying 1428613209 by its sum of digits (36), we get a square (51430075524 = 226782²).

Multiplying 1428613209 by its product of nonzero digits (20736), we get a square (29623723501824 = 5442768²).

It can be divided in two parts, 142861 and 3209, that added together give a triangular number (146070 = T₅₄₀).

The spelling of 1428613209 in words is "one billion, four hundred twenty-eight million, six hundred thirteen thousand, two hundred nine".