4227991 has 2 divisors, whose sum is σ = 4227992. Its totient is φ = 4227990.

The previous prime is 4227989. The next prime is 4228031. The reversal of 4227991 is 1997224.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 4227991 - 2¹ = 4227989 is a prime.

Together with 4227989, it forms a pair of twin primes.

It is an Ulam number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (4227931) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2113995 + 2113996.

It is an arithmetic number, because the mean of its divisors is an integer number (2113996).

Almost surely, 2^4227991 is an apocalyptic number.

4227991 is a deficient number, since it is larger than the sum of its proper divisors (1).

4227991 is an equidigital number, since it uses as much as digits as its factorization.

4227991 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 9072, while the sum is 34.

The square root of 4227991 is about 2056.2079175025. The cubic root of 4227991 is about 161.7004957490.

The spelling of 4227991 in words is "four million, two hundred twenty-seven thousand, nine hundred ninety-one".