691882425664 has 56 divisors (see below), whose sum is σ = 1388325760808. Its totient is φ = 342074327040.

The previous prime is 691882425659. The next prime is 691882425673. The reversal of 691882425664 is 466524288196.

It is a happy number.

691882425664 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 4 ways, for example, as 312436281600 + 379446144064 = 558960^2 + 615992^2 .

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 7109494 + ... + 7206154.

It is an arithmetic number, because the mean of its divisors is an integer number (24791531443).

Almost surely, 2^691882425664 is an apocalyptic number.

691882425664 is a gapful number since it is divisible by the number (64) 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 691882425664, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (694162880404).

691882425664 is an abundant number, since it is smaller than the sum of its proper divisors (696443335144).

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

691882425664 is a wasteful number, since it uses less digits than its factorization.

691882425664 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 97923 (or 97913 counting only the distinct ones).

The product of its digits is 39813120, while the sum is 61.

The spelling of 691882425664 in words is "six hundred ninety-one billion, eight hundred eighty-two million, four hundred twenty-five thousand, six hundred sixty-four".