1971738189 has 6 divisors (see below), whose sum is σ = 2848066286. Its totient is φ = 1314492120.

The previous prime is 1971738187. The next prime is 1971738191. The reversal of 1971738189 is 9818371791.

It is an interprime number because it is at equal distance from previous prime (1971738187) and next prime (1971738191).

It can be written as a sum of positive squares in only one way, i.e., 1359175689 + 612562500 = 36867^2 + 24750^2 .

It is not a de Polignac number, because 1971738189 - 2¹ = 1971738187 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1971738187) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 109541002 + ... + 109541019.

Almost surely, 2^1971738189 is an apocalyptic number.

It is an amenable number.

1971738189 is a deficient number, since it is larger than the sum of its proper divisors (876328097).

1971738189 is a wasteful number, since it uses less digits than its factorization.

1971738189 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 219082027 (or 219082024 counting only the distinct ones).

The product of its digits is 762048, while the sum is 54.

The square root of 1971738189 is about 44404.2586808968. The cubic root of 1971738189 is about 1253.9582661263.

The spelling of 1971738189 in words is "one billion, nine hundred seventy-one million, seven hundred thirty-eight thousand, one hundred eighty-nine".