21125143502 has 16 divisors (see below), whose sum is σ = 34431475200. Its totient is φ = 9683851320.

The previous prime is 21125143499. The next prime is 21125143511. The reversal of 21125143502 is 20534152112.

It is a congruent 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, 8965352 + ... + 8967707.

It is an arithmetic number, because the mean of its divisors is an integer number (2151967200).

Almost surely, 2^21125143502 is an apocalyptic number.

21125143502 is a deficient number, since it is larger than the sum of its proper divisors (13306331698).

21125143502 is a wasteful number, since it uses less digits than its factorization.

21125143502 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17933111.

The product of its (nonzero) digits is 2400, while the sum is 26.

Adding to 21125143502 its reverse (20534152112), we get a palindrome (41659295614).

The spelling of 21125143502 in words is "twenty-one billion, one hundred twenty-five million, one hundred forty-three thousand, five hundred two".