129185890 has 24 divisors (see below), whose sum is σ = 247023252. Its totient is φ = 48633600.

The previous prime is 129185867. The next prime is 129185893. The reversal of 129185890 is 98581921.

It can be written as a sum of positive squares in 6 ways, for example, as 43678881 + 85507009 = 6609^2 + 9247^2 .

It is not an unprimeable number, because it can be changed into a prime (129185893) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 19461 + ... + 25240.

Almost surely, 2^129185890 is an apocalyptic number.

129185890 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

129185890 is a deficient number, since it is larger than the sum of its proper divisors (117837362).

129185890 is a wasteful number, since it uses less digits than its factorization.

129185890 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 44742 (or 44725 counting only the distinct ones).

The product of its (nonzero) digits is 51840, while the sum is 43.

The square root of 129185890 is about 11365.9970966035. The cubic root of 129185890 is about 505.5200211353.

The spelling of 129185890 in words is "one hundred twenty-nine million, one hundred eighty-five thousand, eight hundred ninety".