21405303473513 has 4 divisors (see below), whose sum is σ = 21410982783060. Its totient is φ = 21399624163968.

The previous prime is 21405303473503. The next prime is 21405303473527. The reversal of 21405303473513 is 31537430350412.

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

It can be written as a sum of positive squares in 2 ways, for example, as 16698885626329 + 4706417847184 = 4086427^2 + 2169428^2 .

It is a cyclic number.

It is not a de Polignac number, because 21405303473513 - 2¹⁴ = 21405303457129 is a prime.

It is a super-2 number, since 2×21405303473513² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21405303473503) 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, 2839649120 + ... + 2839656657.

It is an arithmetic number, because the mean of its divisors is an integer number (5352745695765).

Almost surely, 2^{21405303473513} is an apocalyptic number.

It is an amenable number.

21405303473513 is a deficient number, since it is larger than the sum of its proper divisors (5679309547).

21405303473513 is an equidigital number, since it uses as much as digits as its factorization.

21405303473513 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5679309546.

The product of its (nonzero) digits is 453600, while the sum is 41.

The spelling of 21405303473513 in words is "twenty-one trillion, four hundred five billion, three hundred three million, four hundred seventy-three thousand, five hundred thirteen".