21260797 has 2 divisors, whose sum is σ = 21260798. Its totient is φ = 21260796.

The previous prime is 21260749. The next prime is 21260801. The reversal of 21260797 is 79706212.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 18071001 + 3189796 = 4251^2 + 1786^2 .

It is a cyclic number.

It is not a de Polignac number, because 21260797 - 2⁷ = 21260669 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21261797) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10630398 + 10630399.

It is an arithmetic number, because the mean of its divisors is an integer number (10630399).

Almost surely, 2^21260797 is an apocalyptic number.

It is an amenable number.

21260797 is a deficient number, since it is larger than the sum of its proper divisors (1).

21260797 is an equidigital number, since it uses as much as digits as its factorization.

21260797 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 10584, while the sum is 34.

The square root of 21260797 is about 4610.9431790036. The cubic root of 21260797 is about 277.0298160244.

It can be divided in two parts, 212 and 60797, that added together give a square (61009 = 247²).

The spelling of 21260797 in words is "twenty-one million, two hundred sixty thousand, seven hundred ninety-seven".