12129858 has 64 divisors (see below), whose sum is σ = 29877120. Its totient is φ = 3623616.

The previous prime is 12129851. The next prime is 12129863. The reversal of 12129858 is 85892121.

It is a hoax number, since the sum of its digits (36) coincides with the sum of the digits of its distinct prime factors.

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

It is not an unprimeable number, because it can be changed into a prime (12129851) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 25741 + ... + 26207.

It is an arithmetic number, because the mean of its divisors is an integer number (466830).

Almost surely, 2^12129858 is an apocalyptic number.

12129858 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 12129858, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (14938560).

12129858 is an abundant number, since it is smaller than the sum of its proper divisors (17747262).

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

12129858 is a wasteful number, since it uses less digits than its factorization.

12129858 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 528 (or 522 counting only the distinct ones).

The product of its digits is 11520, while the sum is 36.

The square root of 12129858 is about 3482.7945675851. The cubic root of 12129858 is about 229.7657223788.

The spelling of 12129858 in words is "twelve million, one hundred twenty-nine thousand, eight hundred fifty-eight".