691998960 has 80 divisors (see below), whose sum is σ = 2165325696. Its totient is φ = 182801664.

The previous prime is 691998949. The next prime is 691999013. The reversal of 691998960 is 69899196.

It is a tau number, because it is divible by the number of its divisors (80).

It is a self number, because there is not a number n which added to its sum of digits gives 691998960.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 12207 + ... + 39153.

Almost surely, 2^691998960 is an apocalyptic number.

691998960 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 691998960, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1082662848).

691998960 is an abundant number, since it is smaller than the sum of its proper divisors (1473326736).

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

691998960 is a wasteful number, since it uses less digits than its factorization.

691998960 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 27070 (or 27064 counting only the distinct ones).

The product of its (nonzero) digits is 1889568, while the sum is 57.

The square root of 691998960 is about 26305.8731084904. The cubic root of 691998960 is about 884.5080990766.

The spelling of 691998960 in words is "six hundred ninety-one million, nine hundred ninety-eight thousand, nine hundred sixty".