1212531389 has 4 divisors (see below), whose sum is σ = 1219792224. Its totient is φ = 1205270556.

The previous prime is 1212531377. The next prime is 1212531391. The reversal of 1212531389 is 9831352121.

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 1212531389 - 2²⁴ = 1195754173 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 (1212531589) 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, 3630167 + ... + 3630500.

It is an arithmetic number, because the mean of its divisors is an integer number (304948056).

Almost surely, 2^1212531389 is an apocalyptic number.

It is an amenable number.

1212531389 is a deficient number, since it is larger than the sum of its proper divisors (7260835).

1212531389 is an equidigital number, since it uses as much as digits as its factorization.

1212531389 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7260834.

The product of its digits is 12960, while the sum is 35.

The square root of 1212531389 is about 34821.4214098161. The cubic root of 1212531389 is about 1066.3448193804.

The spelling of 1212531389 in words is "one billion, two hundred twelve million, five hundred thirty-one thousand, three hundred eighty-nine".