21530133511 has 2 divisors, whose sum is σ = 21530133512. Its totient is φ = 21530133510.

The previous prime is 21530133479. The next prime is 21530133553. The reversal of 21530133511 is 11533103512.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21530133511 - 2⁵ = 21530133479 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21530133011) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10765066755 + 10765066756.

It is an arithmetic number, because the mean of its divisors is an integer number (10765066756).

Almost surely, 2^21530133511 is an apocalyptic number.

21530133511 is a deficient number, since it is larger than the sum of its proper divisors (1).

21530133511 is an equidigital number, since it uses as much as digits as its factorization.

21530133511 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1350, while the sum is 25.

The spelling of 21530133511 in words is "twenty-one billion, five hundred thirty million, one hundred thirty-three thousand, five hundred eleven".