69856640 has 128 divisors (see below), whose sum is σ = 197406720. Its totient is φ = 23132160.

The previous prime is 69856627. The next prime is 69856663. The reversal of 69856640 is 4665896.

It is a tau number, because it is divible by the number of its divisors (128).

It is a junction number, because it is equal to n+sod(n) for n = 69856591 and 69856600.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 138629 + ... + 139131.

It is an arithmetic number, because the mean of its divisors is an integer number (1542240).

Almost surely, 2^69856640 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 69856640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (98703360).

69856640 is an abundant number, since it is smaller than the sum of its proper divisors (127550080).

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

69856640 is a wasteful number, since it uses less digits than its factorization.

69856640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 560 (or 548 counting only the distinct ones).

The product of its (nonzero) digits is 311040, while the sum is 44.

The square root of 69856640 is about 8358.0284756634. The cubic root of 69856640 is about 411.8469912864.

The spelling of 69856640 in words is "sixty-nine million, eight hundred fifty-six thousand, six hundred forty".