21312255513 has 8 divisors (see below), whose sum is σ = 30087890208. Its totient is φ = 13372395584.

The previous prime is 21312255511. The next prime is 21312255539. The reversal of 21312255513 is 31555221312.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21312255513 - 2¹ = 21312255511 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21312255511) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 208943631 + ... + 208943732.

It is an arithmetic number, because the mean of its divisors is an integer number (3760986276).

Almost surely, 2^21312255513 is an apocalyptic number.

It is an amenable number.

21312255513 is a deficient number, since it is larger than the sum of its proper divisors (8775634695).

21312255513 is a wasteful number, since it uses less digits than its factorization.

21312255513 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 417887383.

The product of its digits is 9000, while the sum is 30.

Adding to 21312255513 its reverse (31555221312), we get a palindrome (52867476825).

The spelling of 21312255513 in words is "twenty-one billion, three hundred twelve million, two hundred fifty-five thousand, five hundred thirteen".