21123002130 has 64 divisors (see below), whose sum is σ = 51693043968. Its totient is φ = 5522100480.

The previous prime is 21123002099. The next prime is 21123002189. The reversal of 21123002130 is 3120032112.

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 31 ways as a sum of consecutive naturals, for example, 2296140 + ... + 2305320.

It is an arithmetic number, because the mean of its divisors is an integer number (807703812).

Almost surely, 2^21123002130 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21123002130, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25846521984).

21123002130 is an abundant number, since it is smaller than the sum of its proper divisors (30570041838).

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

21123002130 is a wasteful number, since it uses less digits than its factorization.

21123002130 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10691.

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

Adding to 21123002130 its reverse (3120032112), we get a palindrome (24243034242).

The spelling of 21123002130 in words is "twenty-one billion, one hundred twenty-three million, two thousand, one hundred thirty".