21124004010 has 64 divisors (see below), whose sum is σ = 51997196160. Its totient is φ = 5489003520.

The previous prime is 21124003997. The next prime is 21124004017. The reversal of 21124004010 is 1040042112.

It is a Harshad number since it is a multiple of its sum of digits (15).

It is not an unprimeable number, because it can be changed into a prime (21124004017) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1046574 + ... + 1066566.

It is an arithmetic number, because the mean of its divisors is an integer number (812456190).

Almost surely, 2^21124004010 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21124004010, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25998598080).

21124004010 is an abundant number, since it is smaller than the sum of its proper divisors (30873192150).

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

21124004010 is a wasteful number, since it uses less digits than its factorization.

21124004010 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20903.

The product of its (nonzero) digits is 64, while the sum is 15.

Adding to 21124004010 its reverse (1040042112), we get a palindrome (22164046122).

The spelling of 21124004010 in words is "twenty-one billion, one hundred twenty-four million, four thousand, ten".