21235105502 has 32 divisors (see below), whose sum is σ = 34677586944. Its totient is φ = 9694245600.

The previous prime is 21235105481. The next prime is 21235105513. The reversal of 21235105502 is 20550153212.

It is a Harshad number since it is a multiple of its sum of digits (26).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1049243 + ... + 1069289.

It is an arithmetic number, because the mean of its divisors is an integer number (1083674592).

Almost surely, 2^21235105502 is an apocalyptic number.

21235105502 is a deficient number, since it is larger than the sum of its proper divisors (13442481442).

21235105502 is a wasteful number, since it uses less digits than its factorization.

21235105502 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20504.

The product of its (nonzero) digits is 3000, while the sum is 26.

Adding to 21235105502 its reverse (20550153212), we get a palindrome (41785258714).

The spelling of 21235105502 in words is "twenty-one billion, two hundred thirty-five million, one hundred five thousand, five hundred two".