1291979567 has 4 divisors (see below), whose sum is σ = 1292106600. Its totient is φ = 1291852536.

The previous prime is 1291979561. The next prime is 1291979587. The reversal of 1291979567 is 7659791921.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 7659791921 = 2333 ⋅3283237.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1291979567 is a prime.

It is a super-2 number, since 2×1291979567² = 3338422403091014978, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1291979561) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 46793 + ... + 69090.

It is an arithmetic number, because the mean of its divisors is an integer number (323026650).

Almost surely, 2^1291979567 is an apocalyptic number.

1291979567 is a deficient number, since it is larger than the sum of its proper divisors (127033).

1291979567 is a wasteful number, since it uses less digits than its factorization.

1291979567 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 127032.

The product of its digits is 2143260, while the sum is 56.

The square root of 1291979567 is about 35944.1172794659. The cubic root of 1291979567 is about 1089.1437786779.

The spelling of 1291979567 in words is "one billion, two hundred ninety-one million, nine hundred seventy-nine thousand, five hundred sixty-seven".