21279703 has 2 divisors, whose sum is σ = 21279704. Its totient is φ = 21279702.

The previous prime is 21279701. The next prime is 21279721. The reversal of 21279703 is 30797212.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21279703 - 2¹ = 21279701 is a prime.

Together with 21279701, 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 (21279701) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10639851 + 10639852.

It is an arithmetic number, because the mean of its divisors is an integer number (10639852).

Almost surely, 2^21279703 is an apocalyptic number.

21279703 is a deficient number, since it is larger than the sum of its proper divisors (1).

21279703 is an equidigital number, since it uses as much as digits as its factorization.

21279703 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 5292, while the sum is 31.

The square root of 21279703 is about 4612.9928462984. The cubic root of 21279703 is about 277.1119072397. Note that the first 3 decimals are identical.

The spelling of 21279703 in words is "twenty-one million, two hundred seventy-nine thousand, seven hundred three".