11613821551 has 4 divisors (see below), whose sum is σ = 11614764112. Its totient is φ = 11612878992.

The previous prime is 11613821509. The next prime is 11613821561. The reversal of 11613821551 is 15512831611.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 15512831611 = 269 ⋅57668519.

It is a cyclic number.

It is not a de Polignac number, because 11613821551 - 2⁹ = 11613821039 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 (11613821501) 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, 452550 + ... + 477523.

It is an arithmetic number, because the mean of its divisors is an integer number (2903691028).

Almost surely, 2^11613821551 is an apocalyptic number.

11613821551 is a deficient number, since it is larger than the sum of its proper divisors (942561).

11613821551 is an equidigital number, since it uses as much as digits as its factorization.

11613821551 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 942560.

The product of its digits is 7200, while the sum is 34.

The spelling of 11613821551 in words is "eleven billion, six hundred thirteen million, eight hundred twenty-one thousand, five hundred fifty-one".