21020123130 has 128 divisors (see below), whose sum is σ = 54615859200. Its totient is φ = 5160153600.

The previous prime is 21020123077. The next prime is 21020123147. The reversal of 21020123130 is 3132102012.

It is a Harshad number since it is a multiple of its sum of digits (15).

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 6331611 + ... + 6334929.

It is an arithmetic number, because the mean of its divisors is an integer number (426686400).

Almost surely, 2^21020123130 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21020123130, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27307929600).

21020123130 is an abundant number, since it is smaller than the sum of its proper divisors (33595736070).

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

21020123130 is a wasteful number, since it uses less digits than its factorization.

21020123130 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3660.

The product of its (nonzero) digits is 72, while the sum is 15.

Adding to 21020123130 its reverse (3132102012), we get a palindrome (24152225142).

The spelling of 21020123130 in words is "twenty-one billion, twenty million, one hundred twenty-three thousand, one hundred thirty".