21503350513 has 4 divisors (see below), whose sum is σ = 21505904640. Its totient is φ = 21500796388.

The previous prime is 21503350511. The next prime is 21503350537. The reversal of 21503350513 is 31505330512.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 21503350513 - 2¹ = 21503350511 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21503350511) 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, 1264393 + ... + 1281286.

It is an arithmetic number, because the mean of its divisors is an integer number (5376476160).

Almost surely, 2^21503350513 is an apocalyptic number.

It is an amenable number.

21503350513 is a deficient number, since it is larger than the sum of its proper divisors (2554127).

21503350513 is an equidigital number, since it uses as much as digits as its factorization.

21503350513 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2554126.

The product of its (nonzero) digits is 6750, while the sum is 28.

The spelling of 21503350513 in words is "twenty-one billion, five hundred three million, three hundred fifty thousand, five hundred thirteen".