21630380531 has 2 divisors, whose sum is σ = 21630380532. Its totient is φ = 21630380530.

The previous prime is 21630380507. The next prime is 21630380533. The reversal of 21630380531 is 13508303612.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21630380531 - 2³⁴ = 4450511347 is a prime.

It is a super-2 number, since 2×21630380531² (a number of 21 digits) contains 22 as substring.

Together with 21630380533, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (21630380533) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10815190265 + 10815190266.

It is an arithmetic number, because the mean of its divisors is an integer number (10815190266).

Almost surely, 2^21630380531 is an apocalyptic number.

21630380531 is a deficient number, since it is larger than the sum of its proper divisors (1).

21630380531 is an equidigital number, since it uses as much as digits as its factorization.

21630380531 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 12960, while the sum is 32.

The spelling of 21630380531 in words is "twenty-one billion, six hundred thirty million, three hundred eighty thousand, five hundred thirty-one".