21124704401 has 4 divisors (see below), whose sum is σ = 21126287652. Its totient is φ = 21123121152.

The previous prime is 21124704397. The next prime is 21124704421. The reversal of 21124704401 is 10440742112.

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 17102100625 + 4022603776 = 130775^2 + 63424^2 .

It is a cyclic number.

It is not a de Polignac number, because 21124704401 - 2² = 21124704397 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21124704421) 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, 771440 + ... + 798353.

It is an arithmetic number, because the mean of its divisors is an integer number (5281571913).

Almost surely, 2^21124704401 is an apocalyptic number.

It is an amenable number.

21124704401 is a deficient number, since it is larger than the sum of its proper divisors (1583251).

21124704401 is a wasteful number, since it uses less digits than its factorization.

21124704401 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1583250.

The product of its (nonzero) digits is 1792, while the sum is 26.

The spelling of 21124704401 in words is "twenty-one billion, one hundred twenty-four million, seven hundred four thousand, four hundred one".