21124213403 has 32 divisors (see below), whose sum is σ = 22861578240. Its totient is φ = 19471082400.

The previous prime is 21124213393. The next prime is 21124213421. The reversal of 21124213403 is 30431242112.

It is not a de Polignac number, because 21124213403 - 2⁴ = 21124213387 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (23).

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21124213423) 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, 20729828 + ... + 20730846.

It is an arithmetic number, because the mean of its divisors is an integer number (714424320).

Almost surely, 2^21124213403 is an apocalyptic number.

21124213403 is a gapful number since it is divisible by the number (23) formed by its first and last digit.

21124213403 is a deficient number, since it is larger than the sum of its proper divisors (1737364837).

21124213403 is a wasteful number, since it uses less digits than its factorization.

21124213403 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1367.

The product of its (nonzero) digits is 1152, while the sum is 23.

Adding to 21124213403 its reverse (30431242112), we get a palindrome (51555455515).

The spelling of 21124213403 in words is "twenty-one billion, one hundred twenty-four million, two hundred thirteen thousand, four hundred three".