21958230 has 64 divisors (see below), whose sum is σ = 62189568. Its totient is φ = 4855680.

The previous prime is 21958229. The next prime is 21958267. The reversal of 21958230 is 3285912.

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 (13) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 4824 + ... + 8196.

It is an arithmetic number, because the mean of its divisors is an integer number (971712).

Almost surely, 2^21958230 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21958230, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (31094784).

21958230 is an abundant number, since it is smaller than the sum of its proper divisors (40231338).

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

21958230 is a wasteful number, since it uses less digits than its factorization.

21958230 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3421.

The product of its (nonzero) digits is 4320, while the sum is 30.

The square root of 21958230 is about 4685.9609473405. The cubic root of 21958230 is about 280.0264855899.

The spelling of 21958230 in words is "twenty-one million, nine hundred fifty-eight thousand, two hundred thirty".