227421991 has 2 divisors, whose sum is σ = 227421992. Its totient is φ = 227421990.

The previous prime is 227421989. The next prime is 227422009. The reversal of 227421991 is 199124722.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 227421991 - 2¹ = 227421989 is a prime.

Together with 227421989, it forms a pair of twin primes.

It is a self number, because there is not a number n which added to its sum of digits gives 227421991.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (227421941) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 113710995 + 113710996.

It is an arithmetic number, because the mean of its divisors is an integer number (113710996).

Almost surely, 2^227421991 is an apocalyptic number.

227421991 is a deficient number, since it is larger than the sum of its proper divisors (1).

227421991 is an equidigital number, since it uses as much as digits as its factorization.

227421991 is an evil number, because the sum of its binary digits is even.

The product of its digits is 18144, while the sum is 37.

The square root of 227421991 is about 15080.5169341107. The cubic root of 227421991 is about 610.3947914666.

The spelling of 227421991 in words is "two hundred twenty-seven million, four hundred twenty-one thousand, nine hundred ninety-one".