21355346642137 has 2 divisors, whose sum is σ = 21355346642138. Its totient is φ = 21355346642136.

The previous prime is 21355346642129. The next prime is 21355346642239. The reversal of 21355346642137 is 73124664355312.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 14314236629056 + 7041110013081 = 3783416^2 + 2653509^2 .

It is a cyclic number.

It is not a de Polignac number, because 21355346642137 - 2³ = 21355346642129 is a prime.

It is a super-2 number, since 2×21355346642137² (a number of 27 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (21355346652137) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10677673321068 + 10677673321069.

It is an arithmetic number, because the mean of its divisors is an integer number (10677673321069).

Almost surely, 2^{21355346642137} is an apocalyptic number.

It is an amenable number.

21355346642137 is a deficient number, since it is larger than the sum of its proper divisors (1).

21355346642137 is an equidigital number, since it uses as much as digits as its factorization.

21355346642137 is an evil number, because the sum of its binary digits is even.

The product of its digits is 10886400, while the sum is 52.

The spelling of 21355346642137 in words is "twenty-one trillion, three hundred fifty-five billion, three hundred forty-six million, six hundred forty-two thousand, one hundred thirty-seven".