1998737 has 4 divisors (see below), whose sum is σ = 2152500. Its totient is φ = 1844976.

The previous prime is 1998727. The next prime is 1998739. The reversal of 1998737 is 7378991.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 7378991 = 263 ⋅28057.

It can be written as a sum of positive squares in 2 ways, for example, as 421201 + 1577536 = 649^2 + 1256^2 .

It is a cyclic number.

It is not a de Polignac number, because 1998737 - 2¹⁰ = 1997713 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1998739) 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, 76862 + ... + 76887.

It is an arithmetic number, because the mean of its divisors is an integer number (538125).

2^1998737 is an apocalyptic number.

It is an amenable number.

1998737 is a deficient number, since it is larger than the sum of its proper divisors (153763).

1998737 is a wasteful number, since it uses less digits than its factorization.

1998737 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 153762.

The product of its digits is 95256, while the sum is 44.

The square root of 1998737 is about 1413.7669539213. The cubic root of 1998737 is about 125.9655780667.

The spelling of 1998737 in words is "one million, nine hundred ninety-eight thousand, seven hundred thirty-seven".