221402387 has 2 divisors, whose sum is σ = 221402388. Its totient is φ = 221402386.

The previous prime is 221402381. The next prime is 221402437. The reversal of 221402387 is 783204122.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 221402387 - 2⁸ = 221402131 is a prime.

It is not a weakly prime, because it can be changed into another prime (221402381) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 110701193 + 110701194.

It is an arithmetic number, because the mean of its divisors is an integer number (110701194).

Almost surely, 2^221402387 is an apocalyptic number.

221402387 is a deficient number, since it is larger than the sum of its proper divisors (1).

221402387 is an equidigital number, since it uses as much as digits as its factorization.

221402387 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 5376, while the sum is 29.

The square root of 221402387 is about 14879.5963318902. The cubic root of 221402387 is about 604.9610766571.

The spelling of 221402387 in words is "two hundred twenty-one million, four hundred two thousand, three hundred eighty-seven".