691961191740 has 288 divisors, whose sum is σ = 2584640647680. Its totient is φ = 145921678848.

The previous prime is 691961191703. The next prime is 691961191741. The reversal of 691961191740 is 47191169196.

691961191740 is a `hidden beast` number, since 6 + 9 + 1 + 9 + 611 + 9 + 17 + 4 + 0 = 666.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (691961191741) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 35682327 + ... + 35701713.

Almost surely, 2^691961191740 is an apocalyptic number.

691961191740 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 691961191740, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1292320323840).

691961191740 is an abundant number, since it is smaller than the sum of its proper divisors (1892679455940).

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

691961191740 is a wasteful number, since it uses less digits than its factorization.

691961191740 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21601 (or 21596 counting only the distinct ones).

The product of its (nonzero) digits is 734832, while the sum is 54.

The spelling of 691961191740 in words is "six hundred ninety-one billion, nine hundred sixty-one million, one hundred ninety-one thousand, seven hundred forty".