1988892409 has 27 divisors (see below), whose sum is σ = 2427337647. Its totient is φ = 1624757904.

The previous prime is 1988892403. The next prime is 1988892421. The reversal of 1988892409 is 9042988891.

The square root of 1988892409 is 44597.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 342805225 + 1646087184 = 18515^2 + 40572^2 .

It is not a de Polignac number, because 1988892409 - 2⁵ = 1988892377 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1988892403) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 7179979 + ... + 7180255.

Almost surely, 2^1988892409 is an apocalyptic number.

1988892409 is the 44597-th square number.

1988892409 is the 22299-th centered octagonal number.

It is an amenable number.

1988892409 is a deficient number, since it is larger than the sum of its proper divisors (438445238).

1988892409 is an frugal number, since it uses more digits than its factorization.

1988892409 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 614 (or 307 counting only the distinct ones).

The product of its (nonzero) digits is 2985984, while the sum is 58.

The cubic root of 1988892409 is about 1257.5842705904.

The spelling of 1988892409 in words is "one billion, nine hundred eighty-eight million, eight hundred ninety-two thousand, four hundred nine".