691941888 has 360 divisors, whose sum is σ = 2355997644. Its totient is φ = 194641920.

The previous prime is 691941857. The next prime is 691941889. The reversal of 691941888 is 888149196.

It can be written as a sum of positive squares in 2 ways, for example, as 669360384 + 22581504 = 25872^2 + 4752^2 .

It is a nude number because it is divisible by every one of its digits.

It is not an unprimeable number, because it can be changed into a prime (691941889) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 9478620 + ... + 9478692.

Almost surely, 2^691941888 is an apocalyptic number.

691941888 is a gapful number since it is divisible by the number (68) 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 691941888, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1177998822).

691941888 is an abundant number, since it is smaller than the sum of its proper divisors (1664055756).

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

691941888 is a wasteful number, since it uses less digits than its factorization.

691941888 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 136 (or 106 counting only the distinct ones).

The product of its digits is 995328, while the sum is 54.

The square root of 691941888 is about 26304.7883093554. The cubic root of 691941888 is about 884.4837820680.

The spelling of 691941888 in words is "six hundred ninety-one million, nine hundred forty-one thousand, eight hundred eighty-eight".