21375373 has 2 divisors, whose sum is σ = 21375374. Its totient is φ = 21375372.

The previous prime is 21375371. The next prime is 21375379. The reversal of 21375373 is 37357312.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 11377129 + 9998244 = 3373^2 + 3162^2 .

It is a cyclic number.

It is not a de Polignac number, because 21375373 - 2¹ = 21375371 is a prime.

Together with 21375371, 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 (21375371) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10687686 + 10687687.

It is an arithmetic number, because the mean of its divisors is an integer number (10687687).

Almost surely, 2^21375373 is an apocalyptic number.

It is an amenable number.

21375373 is a deficient number, since it is larger than the sum of its proper divisors (1).

21375373 is an equidigital number, since it uses as much as digits as its factorization.

21375373 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 13230, while the sum is 31.

The square root of 21375373 is about 4623.3508411108. The cubic root of 21375373 is about 277.5265694334.

The spelling of 21375373 in words is "twenty-one million, three hundred seventy-five thousand, three hundred seventy-three".