21300997 has 2 divisors, whose sum is σ = 21300998. Its totient is φ = 21300996.

The previous prime is 21300989. The next prime is 21301031. The reversal of 21300997 is 79900312.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 18028516 + 3272481 = 4246^2 + 1809^2 .

It is a cyclic number.

It is not a de Polignac number, because 21300997 - 2³ = 21300989 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21300907) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10650498 + 10650499.

It is an arithmetic number, because the mean of its divisors is an integer number (10650499).

Almost surely, 2^21300997 is an apocalyptic number.

It is an amenable number.

21300997 is a deficient number, since it is larger than the sum of its proper divisors (1).

21300997 is an equidigital number, since it uses as much as digits as its factorization.

21300997 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 3402, while the sum is 31.

The square root of 21300997 is about 4615.3003152558. The cubic root of 21300997 is about 277.2043091212.

The spelling of 21300997 in words is "twenty-one million, three hundred thousand, nine hundred ninety-seven".