21030217331 has 2 divisors, whose sum is σ = 21030217332. Its totient is φ = 21030217330.

The previous prime is 21030217277. The next prime is 21030217333. The reversal of 21030217331 is 13371203012.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21030217331 - 2¹⁸ = 21029955187 is a prime.

It is a super-2 number, since 2×21030217331² (a number of 21 digits) contains 22 as substring.

Together with 21030217333, it forms a pair of twin primes.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 21030217297 and 21030217306.

It is not a weakly prime, because it can be changed into another prime (21030217333) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10515108665 + 10515108666.

It is an arithmetic number, because the mean of its divisors is an integer number (10515108666).

Almost surely, 2^21030217331 is an apocalyptic number.

21030217331 is a deficient number, since it is larger than the sum of its proper divisors (1).

21030217331 is an equidigital number, since it uses as much as digits as its factorization.

21030217331 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 756, while the sum is 23.

The spelling of 21030217331 in words is "twenty-one billion, thirty million, two hundred seventeen thousand, three hundred thirty-one".