64213381 has 2 divisors, whose sum is σ = 64213382. Its totient is φ = 64213380.

The previous prime is 64213379. The next prime is 64213427. The reversal of 64213381 is 18331246.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 46648900 + 17564481 = 6830^2 + 4191^2 .

It is a cyclic number.

It is not a de Polignac number, because 64213381 - 2¹ = 64213379 is a prime.

It is a super-2 number, since 2×64213381² = 8246716598902322, which contains 22 as substring.

Together with 64213379, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (64213481) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 32106690 + 32106691.

It is an arithmetic number, because the mean of its divisors is an integer number (32106691).

Almost surely, 2^64213381 is an apocalyptic number.

It is an amenable number.

64213381 is a deficient number, since it is larger than the sum of its proper divisors (1).

64213381 is an equidigital number, since it uses as much as digits as its factorization.

64213381 is an evil number, because the sum of its binary digits is even.

The product of its digits is 3456, while the sum is 28.

The square root of 64213381 is about 8013.3252149155. The cubic root of 64213381 is about 400.4440506152. Note that the first 3 decimals are identical.

The spelling of 64213381 in words is "sixty-four million, two hundred thirteen thousand, three hundred eighty-one".