23211220 has 24 divisors (see below), whose sum is σ = 49077000. Its totient is φ = 9220992.

The previous prime is 23211169. The next prime is 23211229. The reversal of 23211220 is 2211232.

It can be written as a sum of positive squares in 4 ways, for example, as 515524 + 22695696 = 718^2 + 4764^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 23211220.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (23211229) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 915 + ... + 6874.

It is an arithmetic number, because the mean of its divisors is an integer number (2044875).

Almost surely, 2^23211220 is an apocalyptic number.

23211220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

23211220 is an abundant number, since it is smaller than the sum of its proper divisors (25865780).

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

23211220 is a wasteful number, since it uses less digits than its factorization.

23211220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7947 (or 7945 counting only the distinct ones).

The product of its (nonzero) digits is 48, while the sum is 13.

The square root of 23211220 is about 4817.8024035861. The cubic root of 23211220 is about 285.2545996166.

Adding to 23211220 its reverse (2211232), we get a palindrome (25422452).

The spelling of 23211220 in words is "twenty-three million, two hundred eleven thousand, two hundred twenty".