1971539428 has 6 divisors (see below), whose sum is σ = 3450194006. Its totient is φ = 985769712.

The previous prime is 1971539417. The next prime is 1971539447. The reversal of 1971539428 is 8249351791.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 1450695744 + 520843684 = 38088^2 + 22822^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 246442425 + ... + 246442432.

Almost surely, 2^1971539428 is an apocalyptic number.

It is an amenable number.

1971539428 is a deficient number, since it is larger than the sum of its proper divisors (1478654578).

1971539428 is a wasteful number, since it uses less digits than its factorization.

1971539428 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 492884861 (or 492884859 counting only the distinct ones).

The product of its digits is 544320, while the sum is 49.

The square root of 1971539428 is about 44402.0205396106. The cubic root of 1971539428 is about 1253.9161296372.

The spelling of 1971539428 in words is "one billion, nine hundred seventy-one million, five hundred thirty-nine thousand, four hundred twenty-eight".