4521990 has 64 divisors (see below), whose sum is σ = 12068352. Its totient is φ = 1075200.

The previous prime is 4521977. The next prime is 4522027. The reversal of 4521990 is 991254.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (5) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 23334 + ... + 23526.

It is an arithmetic number, because the mean of its divisors is an integer number (188568).

Almost surely, 2^4521990 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 4521990, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (6034176).

4521990 is an abundant number, since it is smaller than the sum of its proper divisors (7546362).

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

4521990 is a wasteful number, since it uses less digits than its factorization.

4521990 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 285.

The product of its (nonzero) digits is 3240, while the sum is 30.

The square root of 4521990 is about 2126.4971196783. The cubic root of 4521990 is about 165.3648492138.

It can be divided in two parts, 452 and 1990, that added together give a palindrome (2442).

The spelling of 4521990 in words is "four million, five hundred twenty-one thousand, nine hundred ninety".