221425788 has 48 divisors (see below), whose sum is σ = 537022080. Its totient is φ = 70924224.

The previous prime is 221425747. The next prime is 221425793. The reversal of 221425788 is 887524122.

221425788 is digitally balanced in base 2 and base 3, because in such bases 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 15 ways as a sum of consecutive naturals, for example, 77595 + ... + 80397.

It is an arithmetic number, because the mean of its divisors is an integer number (11187960).

Almost surely, 2^221425788 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 221425788, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (268511040).

221425788 is an abundant number, since it is smaller than the sum of its proper divisors (315596292).

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

221425788 is a wasteful number, since it uses less digits than its factorization.

221425788 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3066 (or 3064 counting only the distinct ones).

The product of its digits is 71680, while the sum is 39.

The square root of 221425788 is about 14880.3826563701. The cubic root of 221425788 is about 604.9823895791.

The spelling of 221425788 in words is "two hundred twenty-one million, four hundred twenty-five thousand, seven hundred eighty-eight".