21751038497 has 2 divisors, whose sum is σ = 21751038498. Its totient is φ = 21751038496.

The previous prime is 21751038469. The next prime is 21751038539. The reversal of 21751038497 is 79483015712.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 18509330401 + 3241708096 = 136049^2 + 56936^2 .

It is a cyclic number.

It is not a de Polignac number, because 21751038497 - 2¹⁶ = 21750972961 is a prime.

It is not a weakly prime, because it can be changed into another prime (21751038437) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10875519248 + 10875519249.

It is an arithmetic number, because the mean of its divisors is an integer number (10875519249).

Almost surely, 2^21751038497 is an apocalyptic number.

It is an amenable number.

21751038497 is a deficient number, since it is larger than the sum of its proper divisors (1).

21751038497 is an equidigital number, since it uses as much as digits as its factorization.

21751038497 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 423360, while the sum is 47.

The spelling of 21751038497 in words is "twenty-one billion, seven hundred fifty-one million, thirty-eight thousand, four hundred ninety-seven".