221644051 has 2 divisors, whose sum is σ = 221644052. Its totient is φ = 221644050.

The previous prime is 221644021. The next prime is 221644069. The reversal of 221644051 is 150446122.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 221644051 - 2⁵ = 221644019 is a prime.

It is not a weakly prime, because it can be changed into another prime (221644001) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 110822025 + 110822026.

It is an arithmetic number, because the mean of its divisors is an integer number (110822026).

Almost surely, 2^221644051 is an apocalyptic number.

221644051 is a deficient number, since it is larger than the sum of its proper divisors (1).

221644051 is an equidigital number, since it uses as much as digits as its factorization.

221644051 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1920, while the sum is 25.

The square root of 221644051 is about 14887.7147675525. The cubic root of 221644051 is about 605.1811046277.

The spelling of 221644051 in words is "two hundred twenty-one million, six hundred forty-four thousand, fifty-one".