21034357 has 2 divisors, whose sum is σ = 21034358. Its totient is φ = 21034356.

The previous prime is 21034331. The next prime is 21034369. The reversal of 21034357 is 75343012.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 19000881 + 2033476 = 4359^2 + 1426^2 .

It is a cyclic number.

It is not a de Polignac number, because 21034357 - 2⁷ = 21034229 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21034757) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10517178 + 10517179.

It is an arithmetic number, because the mean of its divisors is an integer number (10517179).

Almost surely, 2^21034357 is an apocalyptic number.

It is an amenable number.

21034357 is a deficient number, since it is larger than the sum of its proper divisors (1).

21034357 is an equidigital number, since it uses as much as digits as its factorization.

21034357 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2520, while the sum is 25.

The square root of 21034357 is about 4586.3228189913. The cubic root of 21034357 is about 276.0427933716.

Adding to 21034357 its reverse (75343012), we get a palindrome (96377369).

The spelling of 21034357 in words is "twenty-one million, thirty-four thousand, three hundred fifty-seven".