221501387 has 2 divisors, whose sum is σ = 221501388. Its totient is φ = 221501386.

The previous prime is 221501359. The next prime is 221501429. The reversal of 221501387 is 783105122.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 221501387 - 2⁶ = 221501323 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (221500387) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 110750693 + 110750694.

It is an arithmetic number, because the mean of its divisors is an integer number (110750694).

Almost surely, 2^221501387 is an apocalyptic number.

221501387 is a deficient number, since it is larger than the sum of its proper divisors (1).

221501387 is an equidigital number, since it uses as much as digits as its factorization.

221501387 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3360, while the sum is 29.

The square root of 221501387 is about 14882.9226632406. The cubic root of 221501387 is about 605.0512325988.

The spelling of 221501387 in words is "two hundred twenty-one million, five hundred one thousand, three hundred eighty-seven".