12289878 has 24 divisors (see below), whose sum is σ = 28195128. Its totient is φ = 3855552.

The previous prime is 12289847. The next prime is 12289891. The reversal of 12289878 is 87898221.

It is a happy number.

It is a super-2 number, since 2×12289878² = 302082202509768, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 19776 + ... + 20387.

It is an arithmetic number, because the mean of its divisors is an integer number (1174797).

Almost surely, 2^12289878 is an apocalyptic number.

12289878 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

12289878 is an abundant number, since it is smaller than the sum of its proper divisors (15905250).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

12289878 is a wasteful number, since it uses less digits than its factorization.

12289878 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 40188 (or 40185 counting only the distinct ones).

The product of its digits is 129024, while the sum is 45.

The square root of 12289878 is about 3505.6922283623. The cubic root of 12289878 is about 230.7716864867.

It can be divided in two parts, 122 and 89878, that added together give a square (90000 = 300²).

The spelling of 12289878 in words is "twelve million, two hundred eighty-nine thousand, eight hundred seventy-eight".