1989920145 has 8 divisors (see below), whose sum is σ = 3183872256. Its totient is φ = 1061290736.

The previous prime is 1989920143. The next prime is 1989920147. The reversal of 1989920145 is 5410299891.

It is an interprime number because it is at equal distance from previous prime (1989920143) and next prime (1989920147).

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

It is a cyclic number.

It is not a de Polignac number, because 1989920145 - 2¹ = 1989920143 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1989920094 and 1989920103.

It is not an unprimeable number, because it can be changed into a prime (1989920143) 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 7 ways as a sum of consecutive naturals, for example, 66330657 + ... + 66330686.

It is an arithmetic number, because the mean of its divisors is an integer number (397984032).

Almost surely, 2^1989920145 is an apocalyptic number.

1989920145 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

1989920145 is a deficient number, since it is larger than the sum of its proper divisors (1193952111).

1989920145 is a wasteful number, since it uses less digits than its factorization.

1989920145 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 132661351.

The product of its (nonzero) digits is 233280, while the sum is 48.

The square root of 1989920145 is about 44608.5209909497. The cubic root of 1989920145 is about 1257.8008470903.

The spelling of 1989920145 in words is "one billion, nine hundred eighty-nine million, nine hundred twenty thousand, one hundred forty-five".