3999645009 has 12 divisors (see below), whose sum is σ = 5784967552. Its totient is φ = 2662875000.

The previous prime is 3999644969. The next prime is 3999645031. The reversal of 3999645009 is 9005469993.

It is not a de Polignac number, because 3999645009 - 2⁹ = 3999644497 is a prime.

It is a super-2 number, since 2×3999645009² = 31994320396037220162, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (3999647009) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 289117 + ... + 302634.

Almost surely, 2^3999645009 is an apocalyptic number.

It is an amenable number.

3999645009 is a deficient number, since it is larger than the sum of its proper divisors (1785322543).

3999645009 is a wasteful number, since it uses less digits than its factorization.

3999645009 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 592508 (or 592505 counting only the distinct ones).

The product of its (nonzero) digits is 2361960, while the sum is 54.

The square root of 3999645009 is about 63242.7466908261. The cubic root of 3999645009 is about 1587.3540911550.

The spelling of 3999645009 in words is "three billion, nine hundred ninety-nine million, six hundred forty-five thousand, nine".