11520420451 has 4 divisors (see below), whose sum is σ = 11543054400. Its totient is φ = 11497786504.

The previous prime is 11520420449. The next prime is 11520420487. The reversal of 11520420451 is 15402402511.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 15402402511 = 113 ⋅136304447.

It is a cyclic number.

It is not a de Polignac number, because 11520420451 - 2¹ = 11520420449 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (11520420421) 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 3 ways as a sum of consecutive naturals, for example, 11316211 + ... + 11317228.

It is an arithmetic number, because the mean of its divisors is an integer number (2885763600).

Almost surely, 2^11520420451 is an apocalyptic number.

11520420451 is a deficient number, since it is larger than the sum of its proper divisors (22633949).

11520420451 is an equidigital number, since it uses as much as digits as its factorization.

11520420451 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22633948.

The product of its (nonzero) digits is 1600, while the sum is 25.

Adding to 11520420451 its reverse (15402402511), we get a palindrome (26922822962).

The spelling of 11520420451 in words is "eleven billion, five hundred twenty million, four hundred twenty thousand, four hundred fifty-one".