21404401124 has 24 divisors (see below), whose sum is σ = 38729946528. Its totient is φ = 10343581760.

The previous prime is 21404401111. The next prime is 21404401129. The reversal of 21404401124 is 42110440412.

It is a self number, because there is not a number n which added to its sum of digits gives 21404401124.

It is not an unprimeable number, because it can be changed into a prime (21404401129) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 592334 + ... + 627429.

It is an arithmetic number, because the mean of its divisors is an integer number (1613747772).

Almost surely, 2^21404401124 is an apocalyptic number.

It is an amenable number.

21404401124 is a deficient number, since it is larger than the sum of its proper divisors (17325545404).

21404401124 is a wasteful number, since it uses less digits than its factorization.

21404401124 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1219915 (or 1219913 counting only the distinct ones).

The product of its (nonzero) digits is 1024, while the sum is 23.

Adding to 21404401124 its reverse (42110440412), we get a palindrome (63514841536).

The spelling of 21404401124 in words is "twenty-one billion, four hundred four million, four hundred one thousand, one hundred twenty-four".