21970239497 has 2 divisors, whose sum is σ = 21970239498. Its totient is φ = 21970239496.

The previous prime is 21970239491. The next prime is 21970239517. The reversal of 21970239497 is 79493207912.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 21815585401 + 154654096 = 147701^2 + 12436^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21970239497 is a prime.

It is not a weakly prime, because it can be changed into another prime (21970239491) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10985119748 + 10985119749.

It is an arithmetic number, because the mean of its divisors is an integer number (10985119749).

Almost surely, 2^21970239497 is an apocalyptic number.

It is an amenable number.

21970239497 is a deficient number, since it is larger than the sum of its proper divisors (1).

21970239497 is an equidigital number, since it uses as much as digits as its factorization.

21970239497 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1714608, while the sum is 53.

The spelling of 21970239497 in words is "twenty-one billion, nine hundred seventy million, two hundred thirty-nine thousand, four hundred ninety-seven".