4221990 has 64 divisors (see below), whose sum is σ = 11865600. Its totient is φ = 1065312.

The previous prime is 4221989. The next prime is 4222003. The reversal of 4221990 is 991224.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 4719 + ... + 5541.

It is an arithmetic number, because the mean of its divisors is an integer number (185400).

Almost surely, 2^4221990 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 4221990, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (5932800).

4221990 is an abundant number, since it is smaller than the sum of its proper divisors (7643610).

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

4221990 is a wasteful number, since it uses less digits than its factorization.

4221990 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 858 (or 852 counting only the distinct ones).

The product of its (nonzero) digits is 1296, while the sum is 27.

The square root of 4221990 is about 2054.7481597510. The cubic root of 4221990 is about 161.6239563135.

The spelling of 4221990 in words is "four million, two hundred twenty-one thousand, nine hundred ninety".