691866240 has 256 divisors, whose sum is σ = 2424401280. Its totient is φ = 166772736.

The previous prime is 691866229. The next prime is 691866251. The reversal of 691866240 is 42668196.

It is an interprime number because it is at equal distance from previous prime (691866229) and next prime (691866251).

It is a junction number, because it is equal to n+sod(n) for n = 691866192 and 691866201.

It is an unprimeable number.

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 31 ways as a sum of consecutive naturals, for example, 1322619 + ... + 1323141.

Almost surely, 2^691866240 is an apocalyptic number.

691866240 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 691866240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1212200640).

691866240 is an abundant number, since it is smaller than the sum of its proper divisors (1732535040).

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

691866240 is a wasteful number, since it uses less digits than its factorization.

691866240 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 611 (or 599 counting only the distinct ones).

The product of its (nonzero) digits is 124416, while the sum is 42.

The square root of 691866240 is about 26303.3503569412. The cubic root of 691866240 is about 884.4515482110.

The spelling of 691866240 in words is "six hundred ninety-one million, eight hundred sixty-six thousand, two hundred forty".