213138828 has 144 divisors (see below), whose sum is σ = 645153600. Its totient is φ = 59270400.

The previous prime is 213138817. The next prime is 213138839. The reversal of 213138828 is 828831312.

213138828 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is an interprime number because it is at equal distance from previous prime (213138817) and next prime (213138839).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 213138792 and 213138801.

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, 506058 + ... + 506478.

Almost surely, 2^213138828 is an apocalyptic number.

213138828 is a gapful number since it is divisible by the number (28) 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 213138828, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (322576800).

213138828 is an abundant number, since it is smaller than the sum of its proper divisors (432014772).

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

213138828 is a wasteful number, since it uses less digits than its factorization.

213138828 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 493 (or 474 counting only the distinct ones).

The product of its digits is 18432, while the sum is 36.

The square root of 213138828 is about 14599.2749135017. The cubic root of 213138828 is about 597.3389824227.

The spelling of 213138828 in words is "two hundred thirteen million, one hundred thirty-eight thousand, eight hundred twenty-eight".