21001342120 has 64 divisors (see below), whose sum is σ = 51563744640. Its totient is φ = 7634630400.

The previous prime is 21001342091. The next prime is 21001342123. The reversal of 21001342120 is 2124310012.

It is a junction number, because it is equal to n+sod(n) for n = 21001342094 and 21001342103.

It is not an unprimeable number, because it can be changed into a prime (21001342123) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2751910 + ... + 2759530.

It is an arithmetic number, because the mean of its divisors is an integer number (805683510).

Almost surely, 2^21001342120 is an apocalyptic number.

21001342120 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21001342120 is an abundant number, since it is smaller than the sum of its proper divisors (30562402520).

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

21001342120 is a wasteful number, since it uses less digits than its factorization.

21001342120 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13906 (or 13902 counting only the distinct ones).

The product of its (nonzero) digits is 96, while the sum is 16.

Adding to 21001342120 its reverse (2124310012), we get a palindrome (23125652132).

The spelling of 21001342120 in words is "twenty-one billion, one million, three hundred forty-two thousand, one hundred twenty".