1998537 has 16 divisors (see below), whose sum is σ = 2851200.
Its totient is φ = 1240832.
The previous prime is 1998533. The next prime is 1998541. The reversal of 1998537 is 7358991.
It is a happy number.
It is an interprime number because it is at equal distance from previous prime (1998533) and next prime (1998541).
It is a cyclic number.
It is not a de Polignac number, because 1998537 - 22 = 1998533 is a prime.
It is an Ulam number.
It is not an unprimeable number, because it can be changed into a prime (1998533) by changing a digit.
It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 7468 + ... + 7730.
It is an arithmetic number, because the mean of its divisors is an integer number (178200).
21998537 is an apocalyptic number.
1998537 is a gapful number since it is divisible by the number (17) formed by its first and last digit.
It is an amenable number.
1998537 is a deficient number, since it is larger than the sum of its proper divisors (852663).
1998537 is a wasteful number, since it uses less digits than its factorization.
1998537 is an evil number, because the sum of its binary digits is even.
The sum of its prime factors is 432.
The product of its digits is 68040, while the sum is 42.
The square root of 1998537 is about 1413.6962191362.
The cubic root of 1998537 is about 125.9613764207.
The spelling of 1998537 in words is "one million, nine hundred ninety-eight thousand, five hundred thirty-seven".