691855487218368 has 1120 divisors, whose sum is σ = 2368166561925120. Its totient is φ = 197794566144000.

The previous prime is 691855487218367. The next prime is 691855487218369. The reversal of 691855487218368 is 863812784558196.

691855487218368 is a `hidden beast` number, since 6 + 9 + 1 + 8 + 5 + 548 + 7 + 2 + 1 + 8 + 3 + 68 = 666.

It is an interprime number because it is at equal distance from previous prime (691855487218367) and next prime (691855487218369).

It is a Harshad number since it is a multiple of its sum of digits (81).

It is not an unprimeable number, because it can be changed into a prime (691855487218367) by changing a digit.

It is a polite number, since it can be written in 159 ways as a sum of consecutive naturals, for example, 12185031003 + ... + 12185087781.

Almost surely, 2^{691855487218368} 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 691855487218368, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1184083280962560).

691855487218368 is an abundant number, since it is smaller than the sum of its proper divisors (1676311074706752).

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

691855487218368 is a wasteful number, since it uses less digits than its factorization.

691855487218368 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 57019 (or 57000 counting only the distinct ones).

The product of its digits is 5573836800, while the sum is 81.

The spelling of 691855487218368 in words is "six hundred ninety-one trillion, eight hundred fifty-five billion, four hundred eighty-seven million, two hundred eighteen thousand, three hundred sixty-eight".