213891864 has 64 divisors (see below), whose sum is σ = 547033440. Its totient is φ = 69672960.

The previous prime is 213891827. The next prime is 213891871. The reversal of 213891864 is 468198312.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 282174 + ... + 282930.

Almost surely, 2^213891864 is an apocalyptic number.

213891864 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 213891864, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (273516720).

213891864 is an abundant number, since it is smaller than the sum of its proper divisors (333141576).

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

213891864 is a wasteful number, since it uses less digits than its factorization.

213891864 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1020 (or 1016 counting only the distinct ones).

The product of its digits is 82944, while the sum is 42.

The square root of 213891864 is about 14625.0423589130. The cubic root of 213891864 is about 598.0416372018.

The spelling of 213891864 in words is "two hundred thirteen million, eight hundred ninety-one thousand, eight hundred sixty-four".