21535423505 has 8 divisors (see below), whose sum is σ = 25899059112. Its totient is φ = 17190638208.

The previous prime is 21535423499. The next prime is 21535423531. The reversal of 21535423505 is 50532453512.

It can be written as a sum of positive squares in 4 ways, for example, as 7948257409 + 13587166096 = 89153^2 + 116564^2 .

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

It is a cyclic number.

It is not a de Polignac number, because 21535423505 - 2²⁶ = 21468314641 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4710062 + ... + 4714631.

It is an arithmetic number, because the mean of its divisors is an integer number (3237382389).

Almost surely, 2^21535423505 is an apocalyptic number.

It is an amenable number.

21535423505 is a deficient number, since it is larger than the sum of its proper divisors (4363635607).

21535423505 is an equidigital number, since it uses as much as digits as its factorization.

21535423505 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9425155.

The product of its (nonzero) digits is 90000, while the sum is 35.

The spelling of 21535423505 in words is "twenty-one billion, five hundred thirty-five million, four hundred twenty-three thousand, five hundred five".