1998787 has 16 divisors (see below), whose sum is σ = 2412544. Its totient is φ = 1620000.

The previous prime is 1998761. The next prime is 1998793. The reversal of 1998787 is 7878991.

It is a cyclic number.

It is not a de Polignac number, because 1998787 - 2¹¹ = 1996739 is a prime.

It is a plaindrome in base 11.

It is a zygodrome in base 2.

It is a self number, because there is not a number n which added to its sum of digits gives 1998787.

It is not an unprimeable number, because it can be changed into a prime (1998727) 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, 13162 + ... + 13312.

It is an arithmetic number, because the mean of its divisors is an integer number (150784).

2^1998787 is an apocalyptic number.

1998787 is a deficient number, since it is larger than the sum of its proper divisors (413757).

1998787 is a wasteful number, since it uses less digits than its factorization.

1998787 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 250.

The product of its digits is 254016, while the sum is 49.

The square root of 1998787 is about 1413.7846370646. The cubic root of 1998787 is about 125.9666284344.

It can be divided in two parts, 19 and 98787, that multiplied together give a triangular number (1876953 = T₁₉₃₇).

The spelling of 1998787 in words is "one million, nine hundred ninety-eight thousand, seven hundred eighty-seven".