21530023500511 has 4 divisors (see below), whose sum is σ = 21530842252272. Its totient is φ = 21529204748752.

The previous prime is 21530023500473. The next prime is 21530023500527. The reversal of 21530023500511 is 11500532003512.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21530023500511 - 2⁷ = 21530023500383 is a prime.

It is a super-2 number, since 2×21530023500511² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21530023500511.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21530023560511) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 409336435 + ... + 409389028.

It is an arithmetic number, because the mean of its divisors is an integer number (5382710563068).

Almost surely, 2^{21530023500511} is an apocalyptic number.

21530023500511 is a deficient number, since it is larger than the sum of its proper divisors (818751761).

21530023500511 is an equidigital number, since it uses as much as digits as its factorization.

21530023500511 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 818751760.

The product of its (nonzero) digits is 4500, while the sum is 28.

The spelling of 21530023500511 in words is "twenty-one trillion, five hundred thirty billion, twenty-three million, five hundred thousand, five hundred eleven".