1291998 has 16 divisors (see below), whose sum is σ = 2595600.
Its totient is φ = 428736.
The previous prime is 1291991. The next prime is 1291999. The reversal of 1291998 is 8991921.
It is a happy number.
It is a congruent number.
It is not an unprimeable number, because it can be changed into a prime (1291991) by changing a digit.
It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1786 + ... + 2402.
It is an arithmetic number, because the mean of its divisors is an integer number (162225).
21291998 is an apocalyptic number.
1291998 is an abundant number, since it is smaller than the sum of its proper divisors (1303602).
It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.
1291998 is a wasteful number, since it uses less digits than its factorization.
1291998 is an evil number, because the sum of its binary digits is even.
The sum of its prime factors is 971.
The product of its digits is 11664, while the sum is 39.
The square root of 1291998 is about 1136.6608993011.
The cubic root of 1291998 is about 108.9148958350.
The spelling of 1291998 in words is "one million, two hundred ninety-one thousand, nine hundred ninety-eight".