221451320 has 32 divisors (see below), whose sum is σ = 498694320. Its totient is φ = 88504320.

The previous prime is 221451301. The next prime is 221451341. The reversal of 221451320 is 23154122.

It is a Harshad number since it is a multiple of its sum of digits (20).

It is a junction number, because it is equal to n+sod(n) for n = 221451292 and 221451301.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 79064 + ... + 81816.

Almost surely, 2^221451320 is an apocalyptic number.

221451320 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

221451320 is an abundant number, since it is smaller than the sum of its proper divisors (277243000).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

221451320 is a wasteful number, since it uses less digits than its factorization.

221451320 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4775 (or 4771 counting only the distinct ones).

The product of its (nonzero) digits is 480, while the sum is 20.

The square root of 221451320 is about 14881.2405396862. The cubic root of 221451320 is about 605.0056416385.

The spelling of 221451320 in words is "two hundred twenty-one million, four hundred fifty-one thousand, three hundred twenty".