1209883402809 has 27 divisors (see below), whose sum is σ = 1762088768037. Its totient is φ = 799960654584.

The previous prime is 1209883402801. The next prime is 1209883402817. The reversal of 1209883402809 is 9082043889021.

The square root of 1209883402809 is 1099947.

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

1209883402809 is a `hidden beast` number, since 12 + 0 + 9 + 8 + 8 + 340 + 280 + 9 = 666.

It is an interprime number because it is at equal distance from previous prime (1209883402801) and next prime (1209883402817).

It is not a de Polignac number, because 1209883402809 - 2³ = 1209883402801 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1209883402801) 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, 419078364 + ... + 419081250.

Almost surely, 2^{1209883402809} is an apocalyptic number.

1209883402809 is the 1099947-th square number.

1209883402809 is the 549974-th centered octagonal number.

It is an amenable number.

1209883402809 is a deficient number, since it is larger than the sum of its proper divisors (552205365228).

1209883402809 is an frugal number, since it uses more digits than its factorization.

1209883402809 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6034 (or 3017 counting only the distinct ones).

The product of its (nonzero) digits is 1990656, while the sum is 54.

The spelling of 1209883402809 in words is "one trillion, two hundred nine billion, eight hundred eighty-three million, four hundred two thousand, eight hundred nine".