21895017829213 has 2 divisors, whose sum is σ = 21895017829214. Its totient is φ = 21895017829212.

The previous prime is 21895017829163. The next prime is 21895017829241. The reversal of 21895017829213 is 31292871059812.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 20495521731204 + 1399496098009 = 4527198^2 + 1183003^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21895017829213 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21895017829253) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10947508914606 + 10947508914607.

It is an arithmetic number, because the mean of its divisors is an integer number (10947508914607).

Almost surely, 2^{21895017829213} is an apocalyptic number.

It is an amenable number.

21895017829213 is a deficient number, since it is larger than the sum of its proper divisors (1).

21895017829213 is an equidigital number, since it uses as much as digits as its factorization.

21895017829213 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 4354560, while the sum is 58.

The spelling of 21895017829213 in words is "twenty-one trillion, eight hundred ninety-five billion, seventeen million, eight hundred twenty-nine thousand, two hundred thirteen".