21133154432981 has 2 divisors, whose sum is σ = 21133154432982. Its totient is φ = 21133154432980.

The previous prime is 21133154432909. The next prime is 21133154432983. The reversal of 21133154432981 is 18923445133112.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 20387401288081 + 745753144900 = 4515241^2 + 863570^2 .

It is a cyclic number.

It is not a de Polignac number, because 21133154432981 - 2³⁰ = 21132080691157 is a prime.

It is a super-3 number, since 3×21133154432981³ (a number of 41 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

Together with 21133154432983, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21133154432983) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10566577216490 + 10566577216491.

It is an arithmetic number, because the mean of its divisors is an integer number (10566577216491).

Almost surely, 2^{21133154432981} is an apocalyptic number.

It is an amenable number.

21133154432981 is a deficient number, since it is larger than the sum of its proper divisors (1).

21133154432981 is an equidigital number, since it uses as much as digits as its factorization.

21133154432981 is an evil number, because the sum of its binary digits is even.

The product of its digits is 622080, while the sum is 47.

The spelling of 21133154432981 in words is "twenty-one trillion, one hundred thirty-three billion, one hundred fifty-four million, four hundred thirty-two thousand, nine hundred eighty-one".