1989708123 has 16 divisors (see below), whose sum is σ = 2949180416. Its totient is φ = 1184937120.

The previous prime is 1989708107. The next prime is 1989708131. The reversal of 1989708123 is 3218079891.

It is not a de Polignac number, because 1989708123 - 2⁴ = 1989708107 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1989708223) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 821665 + ... + 824082.

It is an arithmetic number, because the mean of its divisors is an integer number (184323776).

Almost surely, 2^1989708123 is an apocalyptic number.

1989708123 is a gapful number since it is divisible by the number (13) formed by its first and last digit.

1989708123 is a deficient number, since it is larger than the sum of its proper divisors (959472293).

1989708123 is a wasteful number, since it uses less digits than its factorization.

1989708123 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1645794.

The product of its (nonzero) digits is 217728, while the sum is 48.

The square root of 1989708123 is about 44606.1444534270. The cubic root of 1989708123 is about 1257.7561734512.

The spelling of 1989708123 in words is "one billion, nine hundred eighty-nine million, seven hundred eight thousand, one hundred twenty-three".