21430597 has 2 divisors, whose sum is σ = 21430598. Its totient is φ = 21430596.

The previous prime is 21430573. The next prime is 21430621. The reversal of 21430597 is 79503412.

It is a balanced prime because it is at equal distance from previous prime (21430573) and next prime (21430621).

It can be written as a sum of positive squares in only one way, i.e., 16273156 + 5157441 = 4034^2 + 2271^2 .

It is a cyclic number.

It is not a de Polignac number, because 21430597 - 2¹¹ = 21428549 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21430697) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10715298 + 10715299.

It is an arithmetic number, because the mean of its divisors is an integer number (10715299).

Almost surely, 2^21430597 is an apocalyptic number.

It is an amenable number.

21430597 is a deficient number, since it is larger than the sum of its proper divisors (1).

21430597 is an equidigital number, since it uses as much as digits as its factorization.

21430597 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 7560, while the sum is 31.

The square root of 21430597 is about 4629.3192804126. The cubic root of 21430597 is about 277.7653636704.

The spelling of 21430597 in words is "twenty-one million, four hundred thirty thousand, five hundred ninety-seven".