213428381 has 2 divisors, whose sum is σ = 213428382. Its totient is φ = 213428380.

The previous prime is 213428309. The next prime is 213428401. The reversal of 213428381 is 183824312.

213428381 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 207504025 + 5924356 = 14405^2 + 2434^2 .

It is a cyclic number.

It is not a de Polignac number, because 213428381 - 2¹⁸ = 213166237 is a prime.

It is a super-2 number, since 2×213428381² = 91103347632562322, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (213422381) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 106714190 + 106714191.

It is an arithmetic number, because the mean of its divisors is an integer number (106714191).

Almost surely, 2^213428381 is an apocalyptic number.

It is an amenable number.

213428381 is a deficient number, since it is larger than the sum of its proper divisors (1).

213428381 is an equidigital number, since it uses as much as digits as its factorization.

213428381 is an evil number, because the sum of its binary digits is even.

The product of its digits is 9216, while the sum is 32.

The square root of 213428381 is about 14609.1882389132. The cubic root of 213428381 is about 597.6093586705.

The spelling of 213428381 in words is "two hundred thirteen million, four hundred twenty-eight thousand, three hundred eighty-one".