231211890 has 288 divisors, whose sum is σ = 780539760. Its totient is φ = 47029248.

The previous prime is 231211843. The next prime is 231211891. The reversal of 231211890 is 98112132.

It can be written as a sum of positive squares in 8 ways, for example, as 130028409 + 101183481 = 11403^2 + 10059^2 .

It is not an unprimeable number, because it can be changed into a prime (231211891) by changing a digit.

It is a polite number, since it can be written in 143 ways as a sum of consecutive naturals, for example, 2121156 + ... + 2121264.

Almost surely, 2^231211890 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 231211890, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (390269880).

231211890 is an abundant number, since it is smaller than the sum of its proper divisors (549327870).

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

231211890 is a wasteful number, since it uses less digits than its factorization.

231211890 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 186 (or 176 counting only the distinct ones).

The product of its (nonzero) digits is 864, while the sum is 27.

The square root of 231211890 is about 15205.6532250344. The cubic root of 231211890 is about 613.7667931355.

The spelling of 231211890 in words is "two hundred thirty-one million, two hundred eleven thousand, eight hundred ninety".