123890640 has 160 divisors (see below), whose sum is σ = 409795200. Its totient is φ = 30873600.

The previous prime is 123890609. The next prime is 123890651. The reversal of 123890640 is 46098321.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 460426 + ... + 460694.

It is an arithmetic number, because the mean of its divisors is an integer number (2561220).

Almost surely, 2^123890640 is an apocalyptic number.

123890640 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 123890640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (204897600).

123890640 is an abundant number, since it is smaller than the sum of its proper divisors (285904560).

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

123890640 is a wasteful number, since it uses less digits than its factorization.

123890640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 405 (or 399 counting only the distinct ones).

The product of its (nonzero) digits is 10368, while the sum is 33.

The square root of 123890640 is about 11130.6172335590. The cubic root of 123890640 is about 498.5164558805.

The spelling of 123890640 in words is "one hundred twenty-three million, eight hundred ninety thousand, six hundred forty".