21761351 has 2 divisors, whose sum is σ = 21761352. Its totient is φ = 21761350.

The previous prime is 21761347. The next prime is 21761353. The reversal of 21761351 is 15316712.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21761351 - 2² = 21761347 is a prime.

Together with 21761353, it forms a pair of twin primes.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21761351.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21761353) 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, 10880675 + 10880676.

It is an arithmetic number, because the mean of its divisors is an integer number (10880676).

Almost surely, 2^21761351 is an apocalyptic number.

21761351 is a deficient number, since it is larger than the sum of its proper divisors (1).

21761351 is an equidigital number, since it uses as much as digits as its factorization.

21761351 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1260, while the sum is 26.

The square root of 21761351 is about 4664.9063227465. The cubic root of 21761351 is about 279.1870595434.

The spelling of 21761351 in words is "twenty-one million, seven hundred sixty-one thousand, three hundred fifty-one".