131966691 has 4 divisors (see below), whose sum is σ = 175955592. Its totient is φ = 87977792.

The previous prime is 131966689. The next prime is 131966693. The reversal of 131966691 is 196669131.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 196669131 = 3 ⋅65556377.

It is an interprime number because it is at equal distance from previous prime (131966689) and next prime (131966693).

It is a cyclic number.

It is not a de Polignac number, because 131966691 - 2¹ = 131966689 is a prime.

It is not an unprimeable number, because it can be changed into a prime (131966693) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 21994446 + ... + 21994451.

It is an arithmetic number, because the mean of its divisors is an integer number (43988898).

Almost surely, 2^131966691 is an apocalyptic number.

131966691 is a deficient number, since it is larger than the sum of its proper divisors (43988901).

131966691 is an equidigital number, since it uses as much as digits as its factorization.

131966691 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 43988900.

The product of its digits is 52488, while the sum is 42.

The square root of 131966691 is about 11487.6756134564. The cubic root of 131966691 is about 509.1215056992.

The spelling of 131966691 in words is "one hundred thirty-one million, nine hundred sixty-six thousand, six hundred ninety-one".