20440000021997 has 2 divisors, whose sum is σ = 20440000021998. Its totient is φ = 20440000021996.

The previous prime is 20440000021957. The next prime is 20440000022027. The reversal of 20440000021997 is 79912000004402.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 20424018258436 + 15981763561 = 4519294^2 + 126419^2 .

It is a cyclic number.

It is not a de Polignac number, because 20440000021997 - 2⁴⁴ = 2847813977581 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 20440000021997.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20440000021957) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10220000010998 + 10220000010999.

It is an arithmetic number, because the mean of its divisors is an integer number (10220000010999).

Almost surely, 2^{20440000021997} is an apocalyptic number.

It is an amenable number.

20440000021997 is a deficient number, since it is larger than the sum of its proper divisors (1).

20440000021997 is an equidigital number, since it uses as much as digits as its factorization.

20440000021997 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 36288, while the sum is 38.

The spelling of 20440000021997 in words is "twenty trillion, four hundred forty billion, twenty-one thousand, nine hundred ninety-seven".