1291971136 has 21 divisors (see below), whose sum is σ = 2564325961. Its totient is φ = 645841792.

The previous prime is 1291971119. The next prime is 1291971169. The reversal of 1291971136 is 6311791921.

The square root of 1291971136 is 35944.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 1287374400 + 4596736 = 35880^2 + 2144^2 .

It is a Duffinian number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 285306 + ... + 289798.

Almost surely, 2^1291971136 is an apocalyptic number.

1291971136 is a gapful number since it is divisible by the number (16) formed by its first and last digit.

1291971136 is the 35944-th square number.

It is an amenable number.

1291971136 is a deficient number, since it is larger than the sum of its proper divisors (1272354825).

1291971136 is an frugal number, since it uses more digits than its factorization.

1291971136 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8998 (or 4495 counting only the distinct ones).

The product of its digits is 20412, while the sum is 40.

The cubic root of 1291971136 is about 1089.1414095509.

The spelling of 1291971136 in words is "one billion, two hundred ninety-one million, nine hundred seventy-one thousand, one hundred thirty-six".