21302612306531 has 2 divisors, whose sum is σ = 21302612306532. Its totient is φ = 21302612306530.

The previous prime is 21302612306501. The next prime is 21302612306579. The reversal of 21302612306531 is 13560321620312.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21302612306531 - 2¹⁴ = 21302612290147 is a prime.

It is a super-2 number, since 2×21302612306531² (a number of 27 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21302612306491 and 21302612306500.

It is not a weakly prime, because it can be changed into another prime (21302612306501) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10651306153265 + 10651306153266.

It is an arithmetic number, because the mean of its divisors is an integer number (10651306153266).

Almost surely, 2^{21302612306531} is an apocalyptic number.

21302612306531 is a deficient number, since it is larger than the sum of its proper divisors (1).

21302612306531 is an equidigital number, since it uses as much as digits as its factorization.

21302612306531 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 38880, while the sum is 35.

Adding to 21302612306531 its reverse (13560321620312), we get a palindrome (34862933926843).

The spelling of 21302612306531 in words is "twenty-one trillion, three hundred two billion, six hundred twelve million, three hundred six thousand, five hundred thirty-one".