11503320551 has 4 divisors (see below), whose sum is σ = 11504273592. Its totient is φ = 11502367512.

The previous prime is 11503320539. The next prime is 11503320571. The reversal of 11503320551 is 15502330511.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 15502330511 = 2273 ⋅6820207.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-11503320551 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 11503320551.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (11503320511) 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, 458180 + ... + 482633.

It is an arithmetic number, because the mean of its divisors is an integer number (2876068398).

Almost surely, 2^11503320551 is an apocalyptic number.

11503320551 is a deficient number, since it is larger than the sum of its proper divisors (953041).

11503320551 is an equidigital number, since it uses as much as digits as its factorization.

11503320551 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 953040.

The product of its (nonzero) digits is 2250, while the sum is 26.

The spelling of 11503320551 in words is "eleven billion, five hundred three million, three hundred twenty thousand, five hundred fifty-one".