1212345678989 has 4 divisors (see below), whose sum is σ = 1214499046656. Its totient is φ = 1210192311324.

The previous prime is 1212345678979. The next prime is 1212345679001. The reversal of 1212345678989 is 9898765432121.

1212345678989 is an esthetic number in base 10, because in such base its adjacent digits differ by 1.

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.

It is a cyclic number.

It is not a de Polignac number, because 1212345678989 - 2¹² = 1212345674893 is a prime.

It is an alternating number because its digits alternate between odd and even.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1212345678979) by changing a digit.

It is an upside-down number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1076682989 + ... + 1076684114.

It is an arithmetic number, because the mean of its divisors is an integer number (303624761664).

Almost surely, 2^{1212345678989} is an apocalyptic number.

It is an amenable number.

1212345678989 is a deficient number, since it is larger than the sum of its proper divisors (2153367667).

1212345678989 is an equidigital number, since it uses as much as digits as its factorization.

1212345678989 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2153367666.

The product of its digits is 52254720, while the sum is 65.

The spelling of 1212345678989 in words is "one trillion, two hundred twelve billion, three hundred forty-five million, six hundred seventy-eight thousand, nine hundred eighty-nine".