221145451 has 2 divisors, whose sum is σ = 221145452. Its totient is φ = 221145450.

The previous prime is 221145439. The next prime is 221145461. The reversal of 221145451 is 154541122.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 221145451 - 2²⁷ = 86927723 is a prime.

It is not a weakly prime, because it can be changed into another prime (221145461) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 110572725 + 110572726.

It is an arithmetic number, because the mean of its divisors is an integer number (110572726).

Almost surely, 2^221145451 is an apocalyptic number.

221145451 is a deficient number, since it is larger than the sum of its proper divisors (1).

221145451 is an equidigital number, since it uses as much as digits as its factorization.

221145451 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1600, while the sum is 25.

The square root of 221145451 is about 14870.9599891870. The cubic root of 221145451 is about 604.7269683025.

Adding to 221145451 its reverse (154541122), we get a palindrome (375686573).

The spelling of 221145451 in words is "two hundred twenty-one million, one hundred forty-five thousand, four hundred fifty-one".