221651420 has 24 divisors (see below), whose sum is σ = 465763200. Its totient is φ = 88604352.

The previous prime is 221651407. The next prime is 221651431. The reversal of 221651420 is 24156122.

It is a happy number.

221651420 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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, 45461 + ... + 50099.

It is an arithmetic number, because the mean of its divisors is an integer number (19406800).

Almost surely, 2^221651420 is an apocalyptic number.

221651420 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

221651420 is an abundant number, since it is smaller than the sum of its proper divisors (244111780).

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

221651420 is a wasteful number, since it uses less digits than its factorization.

221651420 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7037 (or 7035 counting only the distinct ones).

The product of its (nonzero) digits is 960, while the sum is 23.

The square root of 221651420 is about 14887.9622514298. The cubic root of 221651420 is about 605.1878113723.

The spelling of 221651420 in words is "two hundred twenty-one million, six hundred fifty-one thousand, four hundred twenty".