4015991 has 12 divisors (see below), whose sum is σ = 4788000. Its totient is φ = 3356640.

The previous prime is 4015987. The next prime is 4015993. The reversal of 4015991 is 1995104.

It is not a de Polignac number, because 4015991 - 2² = 4015987 is a prime.

It is a super-2 number, since 2×4015991² = 32256367424162, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (4015993) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1010 + ... + 3008.

It is an arithmetic number, because the mean of its divisors is an integer number (399000).

Almost surely, 2^4015991 is an apocalyptic number.

4015991 is a gapful number since it is divisible by the number (41) formed by its first and last digit.

4015991 is a deficient number, since it is larger than the sum of its proper divisors (772009).

4015991 is a wasteful number, since it uses less digits than its factorization.

4015991 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2054 (or 2047 counting only the distinct ones).

The product of its (nonzero) digits is 1620, while the sum is 29.

The square root of 4015991 is about 2003.9937624653. The cubic root of 4015991 is about 158.9513583525.

The spelling of 4015991 in words is "four million, fifteen thousand, nine hundred ninety-one".