4037991 has 4 divisors (see below), whose sum is σ = 5383992. Its totient is φ = 2691992.

The previous prime is 4037987. The next prime is 4038007. The reversal of 4037991 is 1997304.

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

It is a cyclic number.

It is not a de Polignac number, because 4037991 - 2² = 4037987 is a prime.

It is a D-number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (4037951) 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, 672996 + ... + 673001.

It is an arithmetic number, because the mean of its divisors is an integer number (1345998).

Almost surely, 2^4037991 is an apocalyptic number.

4037991 is a deficient number, since it is larger than the sum of its proper divisors (1346001).

4037991 is a wasteful number, since it uses less digits than its factorization.

4037991 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1346000.

The product of its (nonzero) digits is 6804, while the sum is 33.

The square root of 4037991 is about 2009.4753046504. The cubic root of 4037991 is about 159.2410804274.

It can be divided in two parts, 40379 and 91, that added together give a triangular number (40470 = T₂₈₄).

The spelling of 4037991 in words is "four million, thirty-seven thousand, nine hundred ninety-one".