39990001 has 4 divisors (see below), whose sum is σ = 42342372. Its totient is φ = 37637632.

The previous prime is 39989993. The next prime is 39990011. The reversal of 39990001 is 10009993.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 36663025 + 3326976 = 6055^2 + 1824^2 .

It is a cyclic number.

It is not a de Polignac number, because 39990001 - 2³ = 39989993 is a prime.

It is a Smith number, since the sum of its digits (31) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (39990011) 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, 1176160 + ... + 1176193.

It is an arithmetic number, because the mean of its divisors is an integer number (10585593).

Almost surely, 2^39990001 is an apocalyptic number.

39990001 is the 4000-th centered pentagonal number.

It is an amenable number.

39990001 is a deficient number, since it is larger than the sum of its proper divisors (2352371).

39990001 is a wasteful number, since it uses less digits than its factorization.

39990001 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2352370.

The product of its (nonzero) digits is 2187, while the sum is 31.

The square root of 39990001 is about 6323.7647805718. The cubic root of 39990001 is about 341.9666902114.

Adding to 39990001 its reverse (10009993), we get a palindrome (49999994).

The spelling of 39990001 in words is "thirty-nine million, nine hundred ninety thousand, one".