4203991 has 8 divisors (see below), whose sum is σ = 4618368. Its totient is φ = 3795000.

The previous prime is 4203973. The next prime is 4204001. The reversal of 4203991 is 1993024.

It is a happy number.

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

It is not a de Polignac number, because 4203991 - 2⁷ = 4203863 is a prime.

It is an Ulam number.

It is a Duffinian number.

4203991 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (4203911) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 396 + ... + 2926.

It is an arithmetic number, because the mean of its divisors is an integer number (577296).

Almost surely, 2^4203991 is an apocalyptic number.

4203991 is a deficient number, since it is larger than the sum of its proper divisors (414377).

4203991 is a wasteful number, since it uses less digits than its factorization.

4203991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2693.

The product of its (nonzero) digits is 1944, while the sum is 28.

The square root of 4203991 is about 2050.3636262868. The cubic root of 4203991 is about 161.3939531359.

The spelling of 4203991 in words is "four million, two hundred three thousand, nine hundred ninety-one".