21535233525 has 36 divisors (see below), whose sum is σ = 41539078308. Its totient is φ = 10601959680.

The previous prime is 21535233491. The next prime is 21535233541. The reversal of 21535233525 is 52533253512.

21535233525 is a `hidden beast` number, since 2 + 1 + 53 + 52 + 33 + 525 = 666.

It can be written as a sum of positive squares in 6 ways, for example, as 97002801 + 21438230724 = 9849^2 + 146418^2 .

It is not a de Polignac number, because 21535233525 - 2⁷ = 21535233397 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21535233525.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 3678312 + ... + 3684161.

Almost surely, 2^21535233525 is an apocalyptic number.

21535233525 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21535233525 is a deficient number, since it is larger than the sum of its proper divisors (20003844783).

21535233525 is a wasteful number, since it uses less digits than its factorization.

21535233525 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7362502 (or 7362494 counting only the distinct ones).

The product of its digits is 135000, while the sum is 36.

The spelling of 21535233525 in words is "twenty-one billion, five hundred thirty-five million, two hundred thirty-three thousand, five hundred twenty-five".