691023618432 has 384 divisors, whose sum is σ = 2399211360000. Its totient is φ = 186493612032.

The previous prime is 691023618377. The next prime is 691023618437. The reversal of 691023618432 is 234816320196.

691023618432 is a `hidden beast` number, since 6 + 9 + 1 + 0 + 23 + 618 + 4 + 3 + 2 = 666.

It is a tau number, because it is divible by the number of its divisors (384).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (691023618437) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 53465923 + ... + 53478845.

It is an arithmetic number, because the mean of its divisors is an integer number (6247946250).

Almost surely, 2^691023618432 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 691023618432, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1199605680000).

691023618432 is an abundant number, since it is smaller than the sum of its proper divisors (1708187741568).

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

691023618432 is a wasteful number, since it uses less digits than its factorization.

691023618432 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13318 (or 13303 counting only the distinct ones).

The product of its (nonzero) digits is 373248, while the sum is 45.

The spelling of 691023618432 in words is "six hundred ninety-one billion, twenty-three million, six hundred eighteen thousand, four hundred thirty-two".