3942945409 has 4 divisors (see below), whose sum is σ = 4246248916. Its totient is φ = 3639641904.

The previous prime is 3942945403. The next prime is 3942945421. The reversal of 3942945409 is 9045492493.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 9045492493 = 283 ⋅31962871.

It can be written as a sum of positive squares in 2 ways, for example, as 2563194384 + 1379751025 = 50628^2 + 37145^2 .

It is a cyclic number.

It is not a de Polignac number, because 3942945409 - 2²¹ = 3940848257 is a prime.

It is not an unprimeable number, because it can be changed into a prime (3942945403) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 151651734 + ... + 151651759.

It is an arithmetic number, because the mean of its divisors is an integer number (1061562229).

Almost surely, 2^3942945409 is an apocalyptic number.

It is an amenable number.

3942945409 is a deficient number, since it is larger than the sum of its proper divisors (303303507).

3942945409 is a wasteful number, since it uses less digits than its factorization.

3942945409 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 303303506.

The product of its (nonzero) digits is 1399680, while the sum is 49.

The square root of 3942945409 is about 62792.8770562394. The cubic root of 3942945409 is about 1579.8175040247.

The spelling of 3942945409 in words is "three billion, nine hundred forty-two million, nine hundred forty-five thousand, four hundred nine".