21344203997 has 2 divisors, whose sum is σ = 21344203998. Its totient is φ = 21344203996.

The previous prime is 21344203973. The next prime is 21344204009. The reversal of 21344203997 is 79930244312.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 19594120441 + 1750083556 = 139979^2 + 41834^2 .

It is a cyclic number.

It is not a de Polignac number, because 21344203997 - 2¹² = 21344199901 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21344203967) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10672101998 + 10672101999.

It is an arithmetic number, because the mean of its divisors is an integer number (10672101999).

Almost surely, 2^21344203997 is an apocalyptic number.

It is an amenable number.

21344203997 is a deficient number, since it is larger than the sum of its proper divisors (1).

21344203997 is an equidigital number, since it uses as much as digits as its factorization.

21344203997 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 326592, while the sum is 44.

The spelling of 21344203997 in words is "twenty-one billion, three hundred forty-four million, two hundred three thousand, nine hundred ninety-seven".