213122520 has 288 divisors, whose sum is σ = 781073280. Its totient is φ = 50319360.

The previous prime is 213122501. The next prime is 213122521. The reversal of 213122520 is 25221312.

213122520 is a `hidden beast` number, since 21 + 3 + 122 + 520 = 666.

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 = 213122493 and 213122502.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (213122521) by changing a digit.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 1885984 + ... + 1886096.

It is an arithmetic number, because the mean of its divisors is an integer number (2712060).

Almost surely, 2^213122520 is an apocalyptic number.

213122520 is a gapful number since it is divisible by the number (20) 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 213122520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (390536640).

213122520 is an abundant number, since it is smaller than the sum of its proper divisors (567950760).

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

213122520 is a wasteful number, since it uses less digits than its factorization.

213122520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 187 (or 167 counting only the distinct ones).

The product of its (nonzero) digits is 240, while the sum is 18.

The square root of 213122520 is about 14598.7163819289. The cubic root of 213122520 is about 597.3237471999.

Adding to 213122520 its reverse (25221312), we get a palindrome (238343832).

It can be divided in two parts, 21312 and 2520, that added together give a palindrome (23832).

The spelling of 213122520 in words is "two hundred thirteen million, one hundred twenty-two thousand, five hundred twenty".