20211493 has 2 divisors, whose sum is σ = 20211494. Its totient is φ = 20211492.

The previous prime is 20211491. The next prime is 20211517. The reversal of 20211493 is 39411202.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 17833729 + 2377764 = 4223^2 + 1542^2 .

It is a cyclic number.

It is not a de Polignac number, because 20211493 - 2¹ = 20211491 is a prime.

Together with 20211491, 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 (20211491) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10105746 + 10105747.

It is an arithmetic number, because the mean of its divisors is an integer number (10105747).

Almost surely, 2^20211493 is an apocalyptic number.

It is an amenable number.

20211493 is a deficient number, since it is larger than the sum of its proper divisors (1).

20211493 is an equidigital number, since it uses as much as digits as its factorization.

20211493 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 432, while the sum is 22.

The square root of 20211493 is about 4495.7194085040. The cubic root of 20211493 is about 272.3952092657.

Adding to 20211493 its reverse (39411202), we get a palindrome (59622695).

The spelling of 20211493 in words is "twenty million, two hundred eleven thousand, four hundred ninety-three".