21669315934381 has 2 divisors, whose sum is σ = 21669315934382. Its totient is φ = 21669315934380.

The previous prime is 21669315934373. The next prime is 21669315934421. The reversal of 21669315934381 is 18343951396612.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 21501305302500 + 168010631881 = 4636950^2 + 409891^2 .

It is a cyclic number.

It is not a de Polignac number, because 21669315934381 - 2³ = 21669315934373 is a prime.

It is a super-2 number, since 2×21669315934381² (a number of 27 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21669315934351) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10834657967190 + 10834657967191.

It is an arithmetic number, because the mean of its divisors is an integer number (10834657967191).

Almost surely, 2^{21669315934381} is an apocalyptic number.

It is an amenable number.

21669315934381 is a deficient number, since it is larger than the sum of its proper divisors (1).

21669315934381 is an equidigital number, since it uses as much as digits as its factorization.

21669315934381 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 25194240, while the sum is 61.

The spelling of 21669315934381 in words is "twenty-one trillion, six hundred sixty-nine billion, three hundred fifteen million, nine hundred thirty-four thousand, three hundred eighty-one".