21055131060 has 96 divisors (see below), whose sum is σ = 59731499520. Its totient is φ = 5541101568.

The previous prime is 21055131059. The next prime is 21055131101. The reversal of 21055131060 is 6013155012.

It is a self number, because there is not a number n which added to its sum of digits gives 21055131060.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1674517 + ... + 1687043.

It is an arithmetic number, because the mean of its divisors is an integer number (622203120).

Almost surely, 2^21055131060 is an apocalyptic number.

21055131060 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21055131060, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (29865749760).

21055131060 is an abundant number, since it is smaller than the sum of its proper divisors (38676368460).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21055131060 is a wasteful number, since it uses less digits than its factorization.

21055131060 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12905 (or 12903 counting only the distinct ones).

The product of its (nonzero) digits is 900, while the sum is 24.

Adding to 21055131060 its reverse (6013155012), we get a palindrome (27068286072).

The spelling of 21055131060 in words is "twenty-one billion, fifty-five million, one hundred thirty-one thousand, sixty".