21321023130 has 192 divisors, whose sum is σ = 62616872448. Its totient is φ = 4988666880.

The previous prime is 21321023123. The next prime is 21321023131. The reversal of 21321023130 is 3132012312.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is not an unprimeable number, because it can be changed into a prime (21321023131) by changing a digit.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 3393552 + ... + 3399828.

It is an arithmetic number, because the mean of its divisors is an integer number (326129544).

Almost surely, 2^21321023130 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21321023130, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (31308436224).

21321023130 is an abundant number, since it is smaller than the sum of its proper divisors (41295849318).

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

21321023130 is a wasteful number, since it uses less digits than its factorization.

21321023130 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6421 (or 6418 counting only the distinct ones).

The product of its (nonzero) digits is 216, while the sum is 18.

Adding to 21321023130 its reverse (3132012312), we get a palindrome (24453035442).

The spelling of 21321023130 in words is "twenty-one billion, three hundred twenty-one million, twenty-three thousand, one hundred thirty".