11551100421 has 16 divisors (see below), whose sum is σ = 17624067584. Its totient is φ = 6592232304.

The previous prime is 11551100389. The next prime is 11551100447. The reversal of 11551100421 is 12400115511.

It is not a de Polignac number, because 11551100421 - 2⁵ = 11551100389 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (11551100321) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 332935 + ... + 365988.

It is an arithmetic number, because the mean of its divisors is an integer number (1101504224).

Almost surely, 2^11551100421 is an apocalyptic number.

It is an amenable number.

11551100421 is a deficient number, since it is larger than the sum of its proper divisors (6072967163).

11551100421 is an equidigital number, since it uses as much as digits as its factorization.

11551100421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 699720.

The product of its (nonzero) digits is 200, while the sum is 21.

Adding to 11551100421 its reverse (12400115511), we get a palindrome (23951215932).

The spelling of 11551100421 in words is "eleven billion, five hundred fifty-one million, one hundred thousand, four hundred twenty-one".