1939217128 has 8 divisors (see below), whose sum is σ = 3636032130. Its totient is φ = 969608560.

The previous prime is 1939217099. The next prime is 1939217129. The reversal of 1939217128 is 8217129391.

It can be written as a sum of positive squares in only one way, i.e., 1855714084 + 83503044 = 43078^2 + 9138^2 .

It is a tau number, because it is divible by the number of its divisors (8).

It is not an unprimeable number, because it can be changed into a prime (1939217129) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 121201063 + ... + 121201078.

Almost surely, 2^1939217128 is an apocalyptic number.

It is an amenable number.

1939217128 is a deficient number, since it is larger than the sum of its proper divisors (1696815002).

1939217128 is a wasteful number, since it uses less digits than its factorization.

1939217128 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 242402147 (or 242402143 counting only the distinct ones).

The product of its digits is 54432, while the sum is 43.

The square root of 1939217128 is about 44036.5430977501. The cubic root of 1939217128 is about 1247.0259167819.

The spelling of 1939217128 in words is "one billion, nine hundred thirty-nine million, two hundred seventeen thousand, one hundred twenty-eight".