21020020098997 has 2 divisors, whose sum is σ = 21020020098998. Its totient is φ = 21020020098996.

The previous prime is 21020020098991. The next prime is 21020020099031. The reversal of 21020020098997 is 79989002002012.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 12753940842756 + 8266079256241 = 3571266^2 + 2875079^2 .

It is a cyclic number.

It is not a de Polignac number, because 21020020098997 - 2²³ = 21020011710389 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21020020098997.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21020020098991) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10510010049498 + 10510010049499.

It is an arithmetic number, because the mean of its divisors is an integer number (10510010049499).

Almost surely, 2^{21020020098997} is an apocalyptic number.

It is an amenable number.

21020020098997 is a deficient number, since it is larger than the sum of its proper divisors (1).

21020020098997 is an equidigital number, since it uses as much as digits as its factorization.

21020020098997 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 49.

The spelling of 21020020098997 in words is "twenty-one trillion, twenty billion, twenty million, ninety-eight thousand, nine hundred ninety-seven".