21260971 has 2 divisors, whose sum is σ = 21260972. Its totient is φ = 21260970.

The previous prime is 21260917. The next prime is 21260983. The reversal of 21260971 is 17906212.

It is a happy number.

Together with previous prime (21260917) it forms an Ormiston pair, because they use the same digits, order apart.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21260971 - 2⁷ = 21260843 is a prime.

It is a plaindrome in base 16.

It is not a weakly prime, because it can be changed into another prime (21260171) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10630485 + 10630486.

It is an arithmetic number, because the mean of its divisors is an integer number (10630486).

Almost surely, 2^21260971 is an apocalyptic number.

21260971 is a deficient number, since it is larger than the sum of its proper divisors (1).

21260971 is an equidigital number, since it uses as much as digits as its factorization.

21260971 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1512, while the sum is 28.

The square root of 21260971 is about 4610.9620471221. The cubic root of 21260971 is about 277.0305717668.

The spelling of 21260971 in words is "twenty-one million, two hundred sixty thousand, nine hundred seventy-one".