21535423503 has 32 divisors (see below), whose sum is σ = 32753313792. Its totient is φ = 12458661600.

The previous prime is 21535423499. The next prime is 21535423531. The reversal of 21535423503 is 30532453512.

It is not a de Polignac number, because 21535423503 - 2² = 21535423499 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (33).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21535423543) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 343776 + ... + 401562.

It is an arithmetic number, because the mean of its divisors is an integer number (1023541056).

Almost surely, 2^21535423503 is an apocalyptic number.

21535423503 is a gapful number since it is divisible by the number (23) formed by its first and last digit.

21535423503 is a deficient number, since it is larger than the sum of its proper divisors (11217890289).

21535423503 is a wasteful number, since it uses less digits than its factorization.

21535423503 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 58315.

The product of its (nonzero) digits is 54000, while the sum is 33.

The spelling of 21535423503 in words is "twenty-one billion, five hundred thirty-five million, four hundred twenty-three thousand, five hundred three".