213418128784 has 75 divisors (see below), whose sum is σ = 482589939617. Its totient is φ = 91426106688.

The previous prime is 213418128761. The next prime is 213418128799. The reversal of 213418128784 is 487821814312.

It is a happy number.

The square root of 213418128784 is 461972.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 38801120400 + 174617008384 = 196980^2 + 417872^2 .

It is a Harshad number since it is a multiple of its sum of digits (49).

It is a Duffinian 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 14 ways as a sum of consecutive naturals, for example, 90545334 + ... + 90547690.

Almost surely, 2^213418128784 is an apocalyptic number.

213418128784 is the 461972-nd square number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 213418128784

213418128784 is an abundant number, since it is smaller than the sum of its proper divisors (269171810833).

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

213418128784 is an frugal number, since it uses more digits than its factorization.

213418128784 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4750 (or 2366 counting only the distinct ones).

The product of its digits is 688128, while the sum is 49.

Multiplying 213418128784 by its sum of digits (49), we get a square (10457488310416 = 3233804²).

213418128784 divided by its sum of digits (49) gives a square (4355472016 = 65996²).

The spelling of 213418128784 in words is "two hundred thirteen billion, four hundred eighteen million, one hundred twenty-eight thousand, seven hundred eighty-four".