21765532523 has 8 divisors (see below), whose sum is σ = 25956411648. Its totient is φ = 17845032744.

The previous prime is 21765532513. The next prime is 21765532567. The reversal of 21765532523 is 32523556712.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 21765532523 - 2²⁰ = 21764483947 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21765532513) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 67594661 + ... + 67594982.

It is an arithmetic number, because the mean of its divisors is an integer number (3244551456).

Almost surely, 2^21765532523 is an apocalyptic number.

21765532523 is a gapful number since it is divisible by the number (23) formed by its first and last digit.

21765532523 is a deficient number, since it is larger than the sum of its proper divisors (4190879125).

21765532523 is a wasteful number, since it uses less digits than its factorization.

21765532523 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 135189673.

The product of its digits is 378000, while the sum is 41.

The spelling of 21765532523 in words is "twenty-one billion, seven hundred sixty-five million, five hundred thirty-two thousand, five hundred twenty-three".