1988078289 has 4 divisors (see below), whose sum is σ = 2650771056. Its totient is φ = 1325385524.

The previous prime is 1988078221. The next prime is 1988078303. The reversal of 1988078289 is 9828708891.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 9828708891 = 3 ⋅3276236297.

It is a cyclic number.

It is not a de Polignac number, because 1988078289 - 2¹⁷ = 1987947217 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1988078089) 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, 331346379 + ... + 331346384.

It is an arithmetic number, because the mean of its divisors is an integer number (662692764).

Almost surely, 2^1988078289 is an apocalyptic number.

It is an amenable number.

1988078289 is a deficient number, since it is larger than the sum of its proper divisors (662692767).

1988078289 is an equidigital number, since it uses as much as digits as its factorization.

1988078289 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 662692766.

The product of its (nonzero) digits is 4644864, while the sum is 60.

The square root of 1988078289 is about 44587.8715459709. The cubic root of 1988078289 is about 1257.4126567768.

The spelling of 1988078289 in words is "one billion, nine hundred eighty-eight million, seventy-eight thousand, two hundred eighty-nine".