1239920402 has 18 divisors (see below), whose sum is σ = 2164142997. Its totient is φ = 531245064.

The previous prime is 1239920389. The next prime is 1239920413. The reversal of 1239920402 is 2040299321.

It can be written as a sum of positive squares in 2 ways, for example, as 1026497521 + 213422881 = 32039^2 + 14609^2 .

It is an ABA number since it can be written as A⋅B^A, here for A=2, B=24899.

It is a Duffinian number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 346808 + ... + 350364.

Almost surely, 2^1239920402 is an apocalyptic number.

1239920402 is a deficient number, since it is larger than the sum of its proper divisors (924222595).

1239920402 is an frugal number, since it uses more digits than its factorization.

1239920402 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7130 (or 3566 counting only the distinct ones).

The product of its (nonzero) digits is 7776, while the sum is 32.

The square root of 1239920402 is about 35212.5034895277. The cubic root of 1239920402 is about 1074.3140825718.

Multiplying 1239920402 by its sum of digits (32), we get a square (39677452864 = 199192²).

The spelling of 1239920402 in words is "one billion, two hundred thirty-nine million, nine hundred twenty thousand, four hundred two".