1290128890 has 8 divisors (see below), whose sum is σ = 2322232020. Its totient is φ = 516051552.

The previous prime is 1290128881. The next prime is 1290128909. The reversal of 1290128890 is 988210921.

It can be written as a sum of positive squares in 2 ways, for example, as 1217521449 + 72607441 = 34893^2 + 8521^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 64506435 + ... + 64506454.

Almost surely, 2^1290128890 is an apocalyptic number.

1290128890 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

1290128890 is a deficient number, since it is larger than the sum of its proper divisors (1032103130).

1290128890 is a wasteful number, since it uses less digits than its factorization.

1290128890 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 129012896.

The product of its (nonzero) digits is 20736, while the sum is 40.

The square root of 1290128890 is about 35918.3642444920. The cubic root of 1290128890 is about 1088.6234875449.

The spelling of 1290128890 in words is "one billion, two hundred ninety million, one hundred twenty-eight thousand, eight hundred ninety".