221150021 has 2 divisors, whose sum is σ = 221150022. Its totient is φ = 221150020.

The previous prime is 221149967. The next prime is 221150029. The reversal of 221150021 is 120051122.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 178756900 + 42393121 = 13370^2 + 6511^2 .

It is a cyclic number.

It is not a de Polignac number, because 221150021 - 2¹⁰ = 221148997 is a prime.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 221149978 and 221150005.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (221150029) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 110575010 + 110575011.

It is an arithmetic number, because the mean of its divisors is an integer number (110575011).

Almost surely, 2^221150021 is an apocalyptic number.

It is an amenable number.

221150021 is a deficient number, since it is larger than the sum of its proper divisors (1).

221150021 is an equidigital number, since it uses as much as digits as its factorization.

221150021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 40, while the sum is 14.

The square root of 221150021 is about 14871.1136435709. The cubic root of 221150021 is about 604.7311338614.

The spelling of 221150021 in words is "two hundred twenty-one million, one hundred fifty thousand, twenty-one".