221221451 has 8 divisors (see below), whose sum is σ = 241983984. Its totient is φ = 200567520.

The previous prime is 221221447. The next prime is 221221457. The reversal of 221221451 is 154122122.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 221221451 - 2² = 221221447 is a prime.

It is not an unprimeable number, because it can be changed into a prime (221221457) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 22856 + ... + 31061.

It is an arithmetic number, because the mean of its divisors is an integer number (30247998).

Almost surely, 2^221221451 is an apocalyptic number.

221221451 is a deficient number, since it is larger than the sum of its proper divisors (20762533).

221221451 is a wasteful number, since it uses less digits than its factorization.

221221451 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 54301.

The product of its digits is 320, while the sum is 20.

The square root of 221221451 is about 14873.5150855472. The cubic root of 221221451 is about 604.7962349104.

Adding to 221221451 its reverse (154122122), we get a palindrome (375343573).

It can be divided in two parts, 221 and 221451, that multiplied together give a triangular number (48940671 = T₉₈₉₃).

The spelling of 221221451 in words is "two hundred twenty-one million, two hundred twenty-one thousand, four hundred fifty-one".