21204124403 has 32 divisors (see below), whose sum is σ = 27311800320. Its totient is φ = 15976404000.

The previous prime is 21204124397. The next prime is 21204124427. The reversal of 21204124403 is 30442140212.

It is a cyclic number.

It is not a de Polignac number, because 21204124403 - 2⁸ = 21204124147 is a prime.

It is a super-2 number, since 2×21204124403² (a number of 21 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21204124453) 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, 3603818 + ... + 3609696.

It is an arithmetic number, because the mean of its divisors is an integer number (853493760).

Almost surely, 2^21204124403 is an apocalyptic number.

21204124403 is a deficient number, since it is larger than the sum of its proper divisors (6107675917).

21204124403 is a wasteful number, since it uses less digits than its factorization.

21204124403 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7439.

The product of its (nonzero) digits is 1536, while the sum is 23.

Adding to 21204124403 its reverse (30442140212), we get a palindrome (51646264615).

The spelling of 21204124403 in words is "twenty-one billion, two hundred four million, one hundred twenty-four thousand, four hundred three".