991960 has 16 divisors (see below), whose sum is σ = 2232000. Its totient is φ = 396768.

The previous prime is 991957. The next prime is 991961. The reversal of 991960 is 69199.

It is a happy number.

991960 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (991961) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 12360 + ... + 12439.

It is an arithmetic number, because the mean of its divisors is an integer number (139500).

2⁹⁹¹⁹⁶⁰ is an apocalyptic number.

It is an amenable number.

991960 is an abundant number, since it is smaller than the sum of its proper divisors (1240040).

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

991960 is a wasteful number, since it uses less digits than its factorization.

991960 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24810 (or 24806 counting only the distinct ones).

The product of its (nonzero) digits is 4374, while the sum is 34.

The square root of 991960 is about 995.9718871534. The cubic root of 991960 is about 99.7312785346.

Subtracting from 991960 its reverse (69199), we obtain a triangular number (922761 = T₁₃₅₈).

The spelling of 991960 in words is "nine hundred ninety-one thousand, nine hundred sixty".