21320555130 has 288 divisors, whose sum is σ = 67411745856. Its totient is φ = 4833997056.

The previous prime is 21320555077. The next prime is 21320555131. The reversal of 21320555130 is 3155502312.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a junction number, because it is equal to n+sod(n) for n = 21320555094 and 21320555103.

It is not an unprimeable number, because it can be changed into a prime (21320555131) by changing a digit.

It is a polite number, since it can be written in 143 ways as a sum of consecutive naturals, for example, 16311937 + ... + 16313243.

It is an arithmetic number, because the mean of its divisors is an integer number (234068562).

Almost surely, 2^21320555130 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21320555130, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (33705872928).

21320555130 is an abundant number, since it is smaller than the sum of its proper divisors (46091190726).

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

21320555130 is a wasteful number, since it uses less digits than its factorization.

21320555130 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1480 (or 1461 counting only the distinct ones).

The product of its (nonzero) digits is 4500, while the sum is 27.

The spelling of 21320555130 in words is "twenty-one billion, three hundred twenty million, five hundred fifty-five thousand, one hundred thirty".