125639640 has 128 divisors (see below), whose sum is σ = 478656000. Its totient is φ = 28715904.

The previous prime is 125639623. The next prime is 125639653. The reversal of 125639640 is 46936521.

It is a happy number.

125639640 is a `hidden beast` number, since 1 + 2 + 5 + 6 + 3 + 9 + 640 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 125639595 and 125639604.

It is a congruent number.

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 31 ways as a sum of consecutive naturals, for example, 750 + ... + 15869.

It is an arithmetic number, because the mean of its divisors is an integer number (3739500).

Almost surely, 2^125639640 is an apocalyptic number.

125639640 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 125639640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (239328000).

125639640 is an abundant number, since it is smaller than the sum of its proper divisors (353016360).

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

125639640 is a wasteful number, since it uses less digits than its factorization.

125639640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16646 (or 16636 counting only the distinct ones).

The product of its (nonzero) digits is 38880, while the sum is 36.

The square root of 125639640 is about 11208.9089567183. The cubic root of 125639640 is about 500.8514027372.

The spelling of 125639640 in words is "one hundred twenty-five million, six hundred thirty-nine thousand, six hundred forty".