21212100001979 has 2 divisors, whose sum is σ = 21212100001980. Its totient is φ = 21212100001978.

The previous prime is 21212100001927. The next prime is 21212100002047. The reversal of 21212100001979 is 97910000121212.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21212100001979 - 2²⁰ = 21212098953403 is a prime.

It is a super-3 number, since 3×21212100001979³ (a number of 41 digits) contains 333 as substring.

It is not a weakly prime, because it can be changed into another prime (21212100001909) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10606050000989 + 10606050000990.

It is an arithmetic number, because the mean of its divisors is an integer number (10606050000990).

Almost surely, 2^{21212100001979} is an apocalyptic number.

21212100001979 is a deficient number, since it is larger than the sum of its proper divisors (1).

21212100001979 is an equidigital number, since it uses as much as digits as its factorization.

21212100001979 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 4536, while the sum is 35.

The spelling of 21212100001979 in words is "twenty-one trillion, two hundred twelve billion, one hundred million, one thousand, nine hundred seventy-nine".