1998620887 has 16 divisors (see below), whose sum is σ = 2123100000. Its totient is φ = 1876137984.

The previous prime is 1998620881. The next prime is 1998620893. The reversal of 1998620887 is 7880268991.

It is an interprime number because it is at equal distance from previous prime (1998620881) and next prime (1998620893).

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1998620887 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1998620881) 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, 1904739 + ... + 1905787.

It is an arithmetic number, because the mean of its divisors is an integer number (132693750).

Almost surely, 2^1998620887 is an apocalyptic number.

1998620887 is a deficient number, since it is larger than the sum of its proper divisors (124479113).

1998620887 is a wasteful number, since it uses less digits than its factorization.

1998620887 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1890.

The product of its (nonzero) digits is 3483648, while the sum is 58.

The square root of 1998620887 is about 44705.9379389360. The cubic root of 1998620887 is about 1259.6313877220.

The spelling of 1998620887 in words is "one billion, nine hundred ninety-eight million, six hundred twenty thousand, eight hundred eighty-seven".