12216551957 has 4 divisors (see below), whose sum is σ = 12304440960. Its totient is φ = 12128662956.

The previous prime is 12216551947. The next prime is 12216551983. The reversal of 12216551957 is 75915561221.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 75915561221 = 16843 ⋅4507247.

It is a cyclic number.

It is not a de Polignac number, because 12216551957 - 2²² = 12212357653 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12216551947) 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, 43944293 + ... + 43944570.

It is an arithmetic number, because the mean of its divisors is an integer number (3076110240).

Almost surely, 2^12216551957 is an apocalyptic number.

It is an amenable number.

12216551957 is a deficient number, since it is larger than the sum of its proper divisors (87889003).

12216551957 is an equidigital number, since it uses as much as digits as its factorization.

12216551957 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 87889002.

The product of its digits is 189000, while the sum is 44.

The spelling of 12216551957 in words is "twelve billion, two hundred sixteen million, five hundred fifty-one thousand, nine hundred fifty-seven".