1988636400 has 120 divisors (see below), whose sum is σ = 7078110960. Its totient is φ = 530300160.

The previous prime is 1988636399. The next prime is 1988636413. The reversal of 1988636400 is 46368891.

1988636400 is a `hidden beast` number, since 1 + 9 + 8 + 8 + 636 + 4 + 0 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (120).

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 81267 + ... + 102866.

It is an arithmetic number, because the mean of its divisors is an integer number (58984258).

Almost surely, 2^1988636400 is an apocalyptic number.

1988636400 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1988636400 is an abundant number, since it is smaller than the sum of its proper divisors (5089474560).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1988636400 is a wasteful number, since it uses less digits than its factorization.

1988636400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 184160 (or 184143 counting only the distinct ones).

The product of its (nonzero) digits is 248832, while the sum is 45.

The square root of 1988636400 is about 44594.1296585100. The cubic root of 1988636400 is about 1257.5303097854.

The spelling of 1988636400 in words is "one billion, nine hundred eighty-eight million, six hundred thirty-six thousand, four hundred".