21602765813533 has 2 divisors, whose sum is σ = 21602765813534. Its totient is φ = 21602765813532.

The previous prime is 21602765813501. The next prime is 21602765813579. The reversal of 21602765813533 is 33531856720612.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 18629945002564 + 2972820810969 = 4316242^2 + 1724187^2 .

It is a cyclic number.

It is not a de Polignac number, because 21602765813533 - 2⁵ = 21602765813501 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21602765813333) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10801382906766 + 10801382906767.

It is an arithmetic number, because the mean of its divisors is an integer number (10801382906767).

Almost surely, 2^{21602765813533} is an apocalyptic number.

It is an amenable number.

21602765813533 is a deficient number, since it is larger than the sum of its proper divisors (1).

21602765813533 is an equidigital number, since it uses as much as digits as its factorization.

21602765813533 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 5443200, while the sum is 52.

The spelling of 21602765813533 in words is "twenty-one trillion, six hundred two billion, seven hundred sixty-five million, eight hundred thirteen thousand, five hundred thirty-three".