1212479989 has 4 divisors (see below), whose sum is σ = 1385691424. Its totient is φ = 1039268556.

The previous prime is 1212479977. The next prime is 1212480067. The reversal of 1212479989 is 9899742121.

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: 9899742121 = 19 ⋅521039059.

It is a cyclic number.

It is not a de Polignac number, because 1212479989 - 2²¹ = 1210382837 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 (1212479959) 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, 86605707 + ... + 86605720.

It is an arithmetic number, because the mean of its divisors is an integer number (346422856).

Almost surely, 2^1212479989 is an apocalyptic number.

It is an amenable number.

1212479989 is a deficient number, since it is larger than the sum of its proper divisors (173211435).

1212479989 is an equidigital number, since it uses as much as digits as its factorization.

1212479989 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 173211434.

The product of its digits is 653184, while the sum is 52.

The square root of 1212479989 is about 34820.6833505605. The cubic root of 1212479989 is about 1066.3297514823.

The spelling of 1212479989 in words is "one billion, two hundred twelve million, four hundred seventy-nine thousand, nine hundred eighty-nine".