11551547421 has 12 divisors (see below), whose sum is σ = 16920577440. Its totient is φ = 7592565960.

The previous prime is 11551547417. The next prime is 11551547429. The reversal of 11551547421 is 12474515511.

11551547421 is a `hidden beast` number, since 1 + 155 + 15 + 474 + 21 = 666.

It is not a de Polignac number, because 11551547421 - 2² = 11551547417 is a prime.

It is a super-2 number, since 2×11551547421² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (11551547429) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 9038131 + ... + 9039408.

It is an arithmetic number, because the mean of its divisors is an integer number (1410048120).

Almost surely, 2^11551547421 is an apocalyptic number.

It is an amenable number.

11551547421 is a deficient number, since it is larger than the sum of its proper divisors (5369030019).

11551547421 is a wasteful number, since it uses less digits than its factorization.

11551547421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18077616 (or 18077613 counting only the distinct ones).

The product of its digits is 28000, while the sum is 36.

The spelling of 11551547421 in words is "eleven billion, five hundred fifty-one million, five hundred forty-seven thousand, four hundred twenty-one".