212581890 has 96 divisors (see below), whose sum is σ = 579571200. Its totient is φ = 53988480.

The previous prime is 212581883. The next prime is 212581903. The reversal of 212581890 is 98185212.

212581890 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

212581890 is a nontrivial binomial coefficient, being equal to C(20620, 2).

It is an alternating number because its digits alternate between even and odd.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 205675 + ... + 206705.

It is an arithmetic number, because the mean of its divisors is an integer number (6037200).

Almost surely, 2^212581890 is an apocalyptic number.

212581890 is the 20619-th triangular number and also the 10310-th hexagonal number.

It is a practical number, because each smaller number is the sum of distinct divisors of 212581890, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (289785600).

212581890 is an abundant number, since it is smaller than the sum of its proper divisors (366989310).

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

212581890 is a wasteful number, since it uses less digits than its factorization.

212581890 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1152 (or 1149 counting only the distinct ones).

The product of its (nonzero) digits is 11520, while the sum is 36.

The square root of 212581890 is about 14580.1882703894. The cubic root of 212581890 is about 596.8182405024.

The spelling of 212581890 in words is "two hundred twelve million, five hundred eighty-one thousand, eight hundred ninety".