21001013403 has 4 divisors (see below), whose sum is σ = 28001351208. Its totient is φ = 14000675600.

The previous prime is 21001013401. The next prime is 21001013419. The reversal of 21001013403 is 30431010012.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21001013403 - 2¹ = 21001013401 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21001013401) 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, 3500168898 + ... + 3500168903.

It is an arithmetic number, because the mean of its divisors is an integer number (7000337802).

Almost surely, 2^21001013403 is an apocalyptic number.

21001013403 is a deficient number, since it is larger than the sum of its proper divisors (7000337805).

21001013403 is an equidigital number, since it uses as much as digits as its factorization.

21001013403 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7000337804.

The product of its (nonzero) digits is 72, while the sum is 15.

Adding to 21001013403 its reverse (30431010012), we get a palindrome (51432023415).

The spelling of 21001013403 in words is "twenty-one billion, one million, thirteen thousand, four hundred three".