11666456421 has 16 divisors (see below), whose sum is σ = 16125009984. Its totient is φ = 7496699904.

The previous prime is 11666456413. The next prime is 11666456441. The reversal of 11666456421 is 12465466611.

It is a happy number.

It is not a de Polignac number, because 11666456421 - 2³ = 11666456413 is a prime.

It is a super-2 number, since 2×11666456421² (a number of 21 digits) contains 22 as substring.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (11666456441) 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, 479260 + ... + 503013.

It is an arithmetic number, because the mean of its divisors is an integer number (1007813124).

Almost surely, 2^11666456421 is an apocalyptic number.

It is an amenable number.

11666456421 is a deficient number, since it is larger than the sum of its proper divisors (4458553563).

11666456421 is a wasteful number, since it uses less digits than its factorization.

11666456421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 982420.

The product of its digits is 207360, while the sum is 42.

The spelling of 11666456421 in words is "eleven billion, six hundred sixty-six million, four hundred fifty-six thousand, four hundred twenty-one".