21131425550 has 24 divisors (see below), whose sum is σ = 39319005000. Its totient is φ = 8449440480.

The previous prime is 21131425547. The next prime is 21131425571. The reversal of 21131425550 is 5552413112.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 60581 + ... + 214319.

It is an arithmetic number, because the mean of its divisors is an integer number (1638291875).

Almost surely, 2^21131425550 is an apocalyptic number.

21131425550 is a deficient number, since it is larger than the sum of its proper divisors (18187579450).

21131425550 is a wasteful number, since it uses less digits than its factorization.

21131425550 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 156500 (or 156495 counting only the distinct ones).

The product of its (nonzero) digits is 6000, while the sum is 29.

Adding to 21131425550 its reverse (5552413112), we get a palindrome (26683838662).

The spelling of 21131425550 in words is "twenty-one billion, one hundred thirty-one million, four hundred twenty-five thousand, five hundred fifty".