21002123024 has 20 divisors (see below), whose sum is σ = 42833277840. Its totient is φ = 9948373920.

The previous prime is 21002122997. The next prime is 21002123027. The reversal of 21002123024 is 42032120012.

It is a junction number, because it is equal to n+sod(n) for n = 21002122993 and 21002123011.

It is not an unprimeable number, because it can be changed into a prime (21002123027) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 34542662 + ... + 34543269.

It is an arithmetic number, because the mean of its divisors is an integer number (2141663892).

Almost surely, 2^21002123024 is an apocalyptic number.

It is an amenable number.

21002123024 is an abundant number, since it is smaller than the sum of its proper divisors (21831154816).

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

21002123024 is a wasteful number, since it uses less digits than its factorization.

21002123024 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 69085958 (or 69085952 counting only the distinct ones).

The product of its (nonzero) digits is 192, while the sum is 17.

Adding to 21002123024 its reverse (42032120012), we get a palindrome (63034243036).

The spelling of 21002123024 in words is "twenty-one billion, two million, one hundred twenty-three thousand, twenty-four".