21124024001 has 4 divisors (see below), whose sum is σ = 21124470612. Its totient is φ = 21123577392.

The previous prime is 21124023997. The next prime is 21124024013. The reversal of 21124024001 is 10042042112.

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 18740241025 + 2383782976 = 136895^2 + 48824^2 .

It is a cyclic number.

It is not a de Polignac number, because 21124024001 - 2² = 21124023997 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21124024081) 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, 142646 + ... + 250191.

It is an arithmetic number, because the mean of its divisors is an integer number (5281117653).

Almost surely, 2^21124024001 is an apocalyptic number.

It is an amenable number.

21124024001 is a deficient number, since it is larger than the sum of its proper divisors (446611).

21124024001 is an equidigital number, since it uses as much as digits as its factorization.

21124024001 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 446610.

The product of its (nonzero) digits is 128, while the sum is 17.

Adding to 21124024001 its reverse (10042042112), we get a palindrome (31166066113).

The spelling of 21124024001 in words is "twenty-one billion, one hundred twenty-four million, twenty-four thousand, one".