12157780667 has 4 divisors (see below), whose sum is σ = 12797663880. Its totient is φ = 11517897456.

The previous prime is 12157780651. The next prime is 12157780681. The reversal of 12157780667 is 76608775121.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 12157780667 - 2⁴ = 12157780651 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (12157780067) 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, 319941578 + ... + 319941615.

It is an arithmetic number, because the mean of its divisors is an integer number (3199415970).

Almost surely, 2^12157780667 is an apocalyptic number.

12157780667 is a deficient number, since it is larger than the sum of its proper divisors (639883213).

12157780667 is an equidigital number, since it uses as much as digits as its factorization.

12157780667 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 639883212.

The product of its (nonzero) digits is 987840, while the sum is 50.

The spelling of 12157780667 in words is "twelve billion, one hundred fifty-seven million, seven hundred eighty thousand, six hundred sixty-seven".