123645890 has 16 divisors (see below), whose sum is σ = 222773760. Its totient is φ = 49411440.

The previous prime is 123645889. The next prime is 123645911. The reversal of 123645890 is 98546321.

It is a happy number.

It is a super-2 number, since 2×123645890² = 30576612227784200, which contains 22 as substring.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 6431 + ... + 16989.

It is an arithmetic number, because the mean of its divisors is an integer number (13923360).

Almost surely, 2^123645890 is an apocalyptic number.

123645890 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

123645890 is a deficient number, since it is larger than the sum of its proper divisors (99127870).

123645890 is a wasteful number, since it uses less digits than its factorization.

123645890 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11737.

The product of its (nonzero) digits is 51840, while the sum is 38.

The square root of 123645890 is about 11119.6173495314. The cubic root of 123645890 is about 498.1879609621.

The spelling of 123645890 in words is "one hundred twenty-three million, six hundred forty-five thousand, eight hundred ninety".