21051232342531 has 2 divisors, whose sum is σ = 21051232342532. Its totient is φ = 21051232342530.

The previous prime is 21051232342529. The next prime is 21051232342541. The reversal of 21051232342531 is 13524323215012.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21051232342531 - 2¹ = 21051232342529 is a prime.

It is a super-2 number, since 2×21051232342531² (a number of 27 digits) contains 22 as substring.

Together with 21051232342529, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (21051232342541) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10525616171265 + 10525616171266.

It is an arithmetic number, because the mean of its divisors is an integer number (10525616171266).

Almost surely, 2^{21051232342531} is an apocalyptic number.

21051232342531 is a deficient number, since it is larger than the sum of its proper divisors (1).

21051232342531 is an equidigital number, since it uses as much as digits as its factorization.

21051232342531 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 43200, while the sum is 34.

Adding to 21051232342531 its reverse (13524323215012), we get a palindrome (34575555557543).

The spelling of 21051232342531 in words is "twenty-one trillion, fifty-one billion, two hundred thirty-two million, three hundred forty-two thousand, five hundred thirty-one".