131969779 has 4 divisors (see below), whose sum is σ = 134133280. Its totient is φ = 129806280.

The previous prime is 131969777. The next prime is 131969809. The reversal of 131969779 is 977969131.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 977969131 = 23 ⋅42520397.

It is a cyclic number.

It is not a de Polignac number, because 131969779 - 2¹ = 131969777 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (131969777) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1081659 + ... + 1081780.

It is an arithmetic number, because the mean of its divisors is an integer number (33533320).

Almost surely, 2^131969779 is an apocalyptic number.

131969779 is a deficient number, since it is larger than the sum of its proper divisors (2163501).

131969779 is an equidigital number, since it uses as much as digits as its factorization.

131969779 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2163500.

The product of its digits is 642978, while the sum is 52.

The square root of 131969779 is about 11487.8100175795. The cubic root of 131969779 is about 509.1254767895.

The spelling of 131969779 in words is "one hundred thirty-one million, nine hundred sixty-nine thousand, seven hundred seventy-nine".