21513555413 has 4 divisors (see below), whose sum is σ = 24586920480. Its totient is φ = 18440190348.

The previous prime is 21513555397. The next prime is 21513555439. The reversal of 21513555413 is 31455531512.

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 21513555413 - 2⁴ = 21513555397 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21513555463) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1536682523 + ... + 1536682536.

It is an arithmetic number, because the mean of its divisors is an integer number (6146730120).

Almost surely, 2^21513555413 is an apocalyptic number.

It is an amenable number.

21513555413 is a deficient number, since it is larger than the sum of its proper divisors (3073365067).

21513555413 is an equidigital number, since it uses as much as digits as its factorization.

21513555413 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3073365066.

The product of its digits is 45000, while the sum is 35.

The spelling of 21513555413 in words is "twenty-one billion, five hundred thirteen million, five hundred fifty-five thousand, four hundred thirteen".