21513454003 has 4 divisors (see below), whose sum is σ = 21772652328. Its totient is φ = 21254255680.

The previous prime is 21513453971. The next prime is 21513454013. The reversal of 21513454003 is 30045431512.

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 21513454003 - 2⁵ = 21513453971 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21513454013) 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, 129599038 + ... + 129599203.

It is an arithmetic number, because the mean of its divisors is an integer number (5443163082).

Almost surely, 2^21513454003 is an apocalyptic number.

21513454003 is a deficient number, since it is larger than the sum of its proper divisors (259198325).

21513454003 is an equidigital number, since it uses as much as digits as its factorization.

21513454003 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 259198324.

The product of its (nonzero) digits is 7200, while the sum is 28.

Adding to 21513454003 its reverse (30045431512), we get a palindrome (51558885515).

The spelling of 21513454003 in words is "twenty-one billion, five hundred thirteen million, four hundred fifty-four thousand, three".