21297799545991 has 2 divisors, whose sum is σ = 21297799545992. Its totient is φ = 21297799545990.

The previous prime is 21297799545959. The next prime is 21297799546019. The reversal of 21297799545991 is 19954599779212.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21297799545991 - 2⁵ = 21297799545959 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21297799545931) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10648899772995 + 10648899772996.

It is an arithmetic number, because the mean of its divisors is an integer number (10648899772996).

Almost surely, 2^{21297799545991} is an apocalyptic number.

21297799545991 is a deficient number, since it is larger than the sum of its proper divisors (1).

21297799545991 is an equidigital number, since it uses as much as digits as its factorization.

21297799545991 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1157360400, while the sum is 79.

The spelling of 21297799545991 in words is "twenty-one trillion, two hundred ninety-seven billion, seven hundred ninety-nine million, five hundred forty-five thousand, nine hundred ninety-one".