21710783 has 2 divisors, whose sum is σ = 21710784. Its totient is φ = 21710782.

The previous prime is 21710753. The next prime is 21710789. The reversal of 21710783 is 38701712.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21710783 - 2¹⁰ = 21709759 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21710789) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10855391 + 10855392.

It is an arithmetic number, because the mean of its divisors is an integer number (10855392).

Almost surely, 2^21710783 is an apocalyptic number.

21710783 is a deficient number, since it is larger than the sum of its proper divisors (1).

21710783 is an equidigital number, since it uses as much as digits as its factorization.

21710783 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2352, while the sum is 29.

The square root of 21710783 is about 4659.4831258413. The cubic root of 21710783 is about 278.9706379176.

The spelling of 21710783 in words is "twenty-one million, seven hundred ten thousand, seven hundred eighty-three".