21000199980029 has 2 divisors, whose sum is σ = 21000199980030. Its totient is φ = 21000199980028.

The previous prime is 21000199979981. The next prime is 21000199980073. The reversal of 21000199980029 is 92008999100012.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 14944796222500 + 6055403757529 = 3865850^2 + 2460773^2 .

It is a cyclic number.

It is not a de Polignac number, because 21000199980029 - 2²⁴ = 21000183202813 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21000199980229) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10500099990014 + 10500099990015.

It is an arithmetic number, because the mean of its divisors is an integer number (10500099990015).

Almost surely, 2^{21000199980029} is an apocalyptic number.

It is an amenable number.

21000199980029 is a deficient number, since it is larger than the sum of its proper divisors (1).

21000199980029 is an equidigital number, since it uses as much as digits as its factorization.

21000199980029 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 209952, while the sum is 50.

The spelling of 21000199980029 in words is "twenty-one trillion, one hundred ninety-nine million, nine hundred eighty thousand, twenty-nine".