221210387 has 2 divisors, whose sum is σ = 221210388. Its totient is φ = 221210386.

The previous prime is 221210359. The next prime is 221210413. The reversal of 221210387 is 783012122.

It is an a-pointer prime, because the next prime (221210413) can be obtained adding 221210387 to its sum of digits (26).

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 221210387 - 2⁶ = 221210323 is a prime.

It is not a weakly prime, because it can be changed into another prime (221210357) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 110605193 + 110605194.

It is an arithmetic number, because the mean of its divisors is an integer number (110605194).

Almost surely, 2^221210387 is an apocalyptic number.

221210387 is a deficient number, since it is larger than the sum of its proper divisors (1).

221210387 is an equidigital number, since it uses as much as digits as its factorization.

221210387 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1344, while the sum is 26.

The square root of 221210387 is about 14873.1431446080. The cubic root of 221210387 is about 604.7861521373.

The spelling of 221210387 in words is "two hundred twenty-one million, two hundred ten thousand, three hundred eighty-seven".