21153413513 has 4 divisors (see below), whose sum is σ = 22073127168. Its totient is φ = 20233699860.

The previous prime is 21153413503. The next prime is 21153413521. The reversal of 21153413513 is 31531435112.

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 21153413513 - 2¹⁶ = 21153347977 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (21153413503) 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, 459856793 + ... + 459856838.

It is an arithmetic number, because the mean of its divisors is an integer number (5518281792).

Almost surely, 2^21153413513 is an apocalyptic number.

21153413513 is a gapful number since it is divisible by the number (23) formed by its first and last digit.

It is an amenable number.

21153413513 is a deficient number, since it is larger than the sum of its proper divisors (919713655).

21153413513 is an equidigital number, since it uses as much as digits as its factorization.

21153413513 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 919713654.

The product of its digits is 5400, while the sum is 29.

Adding to 21153413513 its reverse (31531435112), we get a palindrome (52684848625).

The spelling of 21153413513 in words is "twenty-one billion, one hundred fifty-three million, four hundred thirteen thousand, five hundred thirteen".