691888244040 has 512 divisors, whose sum is σ = 2702136729600. Its totient is φ = 154177551360.

The previous prime is 691888243909. The next prime is 691888244051. The reversal of 691888244040 is 40442888196.

It is a happy number.

691888244040 is a `hidden beast` number, since 6 + 9 + 1 + 88 + 82 + 440 + 40 = 666.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is an unprimeable number.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 205123794 + ... + 205127166.

It is an arithmetic number, because the mean of its divisors is an integer number (5277610800).

Almost surely, 2^691888244040 is an apocalyptic number.

691888244040 is a gapful number since it is divisible by the number (60) 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 691888244040, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1351068364800).

691888244040 is an abundant number, since it is smaller than the sum of its proper divisors (2010248485560).

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

691888244040 is a wasteful number, since it uses less digits than its factorization.

691888244040 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4074 (or 4064 counting only the distinct ones).

The product of its (nonzero) digits is 3538944, while the sum is 54.

The spelling of 691888244040 in words is "six hundred ninety-one billion, eight hundred eighty-eight million, two hundred forty-four thousand, forty".