231220026 has 72 divisors (see below), whose sum is σ = 542653020. Its totient is φ = 70906368.

The previous prime is 231220021. The next prime is 231220027. The reversal of 231220026 is 620022132.

It can be written as a sum of positive squares in 6 ways, for example, as 141633801 + 89586225 = 11901^2 + 9465^2 .

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a junction number, because it is equal to n+sod(n) for n = 231219990 and 231220008.

It is not an unprimeable number, because it can be changed into a prime (231220021) by changing a digit.

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 35 ways as a sum of consecutive naturals, for example, 859420 + ... + 859688.

Almost surely, 2^231220026 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 231220026, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (271326510).

231220026 is an abundant number, since it is smaller than the sum of its proper divisors (311432994).

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

231220026 is a wasteful number, since it uses less digits than its factorization.

231220026 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 400 (or 344 counting only the distinct ones).

The product of its (nonzero) digits is 288, while the sum is 18.

The square root of 231220026 is about 15205.9207547587. The cubic root of 231220026 is about 613.7739922290.

Adding to 231220026 its reverse (620022132), we get a palindrome (851242158).

The spelling of 231220026 in words is "two hundred thirty-one million, two hundred twenty thousand, twenty-six".