21710567 has 2 divisors, whose sum is σ = 21710568. Its totient is φ = 21710566.

The previous prime is 21710537. The next prime is 21710573. The reversal of 21710567 is 76501712.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21710567 - 2⁶ = 21710503 is a prime.

It is a super-2 number, since 2×21710567² = 942697438922978, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21710537) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10855283 + 10855284.

It is an arithmetic number, because the mean of its divisors is an integer number (10855284).

Almost surely, 2^21710567 is an apocalyptic number.

21710567 is a deficient number, since it is larger than the sum of its proper divisors (1).

21710567 is an equidigital number, since it uses as much as digits as its factorization.

21710567 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2940, while the sum is 29.

The square root of 21710567 is about 4659.4599472471. The cubic root of 21710567 is about 278.9697127573.

The spelling of 21710567 in words is "twenty-one million, seven hundred ten thousand, five hundred sixty-seven".