20399232 has 64 divisors (see below), whose sum is σ = 61934400. Its totient is φ = 5827584.

The previous prime is 20399231. The next prime is 20399233. The reversal of 20399232 is 23299302.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (20399231) and next prime (20399233).

It is a tau number, because it is divible by the number of its divisors (64).

It is a super-2 number, since 2×20399232² = 832257332379648, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 20399232.

It is not an unprimeable number, because it can be changed into a prime (20399231) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1107 + ... + 6482.

It is an arithmetic number, because the mean of its divisors is an integer number (967725).

Almost surely, 2^20399232 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 20399232, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (30967200).

20399232 is an abundant number, since it is smaller than the sum of its proper divisors (41535168).

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

20399232 is an equidigital number, since it uses as much as digits as its factorization.

20399232 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7613 (or 7601 counting only the distinct ones).

The product of its (nonzero) digits is 5832, while the sum is 30.

The square root of 20399232 is about 4516.5508964253. The cubic root of 20399232 is about 273.2360126793.

The spelling of 20399232 in words is "twenty million, three hundred ninety-nine thousand, two hundred thirty-two".