123400020 has 24 divisors (see below), whose sum is σ = 345520224. Its totient is φ = 32906656.

The previous prime is 123399989. The next prime is 123400021. The reversal of 123400020 is 20004321.

It is a Harshad number since it is a multiple of its sum of digits (12).

It is a junction number, because it is equal to n+sod(n) for n = 123399969 and 123400005.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (123400021) by changing a digit.

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, 1028274 + ... + 1028393.

It is an arithmetic number, because the mean of its divisors is an integer number (14396676).

Almost surely, 2^123400020 is an apocalyptic number.

123400020 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

123400020 is an abundant number, since it is smaller than the sum of its proper divisors (222120204).

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

123400020 is a wasteful number, since it uses less digits than its factorization.

123400020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2056679 (or 2056677 counting only the distinct ones).

The product of its (nonzero) digits is 48, while the sum is 12.

The square root of 123400020 is about 11108.5561618061. The cubic root of 123400020 is about 497.8575260566.

Adding to 123400020 its reverse (20004321), we get a palindrome (143404341).

The spelling of 123400020 in words is "one hundred twenty-three million, four hundred thousand, twenty".