21120024001 has 4 divisors (see below), whose sum is σ = 22362378372. Its totient is φ = 19877669632.

The previous prime is 21120023987. The next prime is 21120024067. The reversal of 21120024001 is 10042002112.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 13906069776 + 7213954225 = 117924^2 + 84935^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21120024001 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21120024701) 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, 621177160 + ... + 621177193.

It is an arithmetic number, because the mean of its divisors is an integer number (5590594593).

Almost surely, 2^21120024001 is an apocalyptic number.

It is an amenable number.

21120024001 is a deficient number, since it is larger than the sum of its proper divisors (1242354371).

21120024001 is a wasteful number, since it uses less digits than its factorization.

21120024001 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1242354370.

The product of its (nonzero) digits is 32, while the sum is 13.

Adding to 21120024001 its reverse (10042002112), we get a palindrome (31162026113).

The spelling of 21120024001 in words is "twenty-one billion, one hundred twenty million, twenty-four thousand, one".