21000001203120 has 80 divisors (see below), whose sum is σ = 65100691369440. Its totient is φ = 5599941169152.

The previous prime is 21000001203101. The next prime is 21000001203121. The reversal of 21000001203120 is 2130210000012.

It is a tau number, because it is divible by the number of its divisors (80).

It is a Harshad number since it is a multiple of its sum of digits (12).

It is a junction number, because it is equal to n+sod(n) for n = 21000001203096 and 21000001203105.

It is not an unprimeable number, because it can be changed into a prime (21000001203121) 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, 25289896 + ... + 26107064.

It is an arithmetic number, because the mean of its divisors is an integer number (813758642118).

Almost surely, 2^{21000001203120} is an apocalyptic number.

21000001203120 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21000001203120 is an abundant number, since it is smaller than the sum of its proper divisors (44100690166320).

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

21000001203120 is a wasteful number, since it uses less digits than its factorization.

21000001203120 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 924262 (or 924256 counting only the distinct ones).

The product of its (nonzero) digits is 24, while the sum is 12.

Adding to 21000001203120 its reverse (2130210000012), we get a palindrome (23130211203132).

The spelling of 21000001203120 in words is "twenty-one trillion, one million, two hundred three thousand, one hundred twenty".