4001990 has 8 divisors (see below), whose sum is σ = 7203600. Its totient is φ = 1600792.

The previous prime is 4001947. The next prime is 4001999. The reversal of 4001990 is 991004.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (4001999) 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, 200090 + ... + 200109.

It is an arithmetic number, because the mean of its divisors is an integer number (900450).

Almost surely, 2^4001990 is an apocalyptic number.

4001990 is a deficient number, since it is larger than the sum of its proper divisors (3201610).

4001990 is a wasteful number, since it uses less digits than its factorization.

4001990 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 400206.

The product of its (nonzero) digits is 324, while the sum is 23.

The square root of 4001990 is about 2000.4974381388. The cubic root of 4001990 is about 158.7664252333.

Adding to 4001990 its reverse (991004), we get a palindrome (4992994).

The spelling of 4001990 in words is "four million, one thousand, nine hundred ninety".