131878721 has 8 divisors (see below), whose sum is σ = 145326720. Its totient is φ = 118902672.

The previous prime is 131878717. The next prime is 131878723. The reversal of 131878721 is 127878131.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 131878721 - 2² = 131878717 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (131878723) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 117401 + ... + 118518.

It is an arithmetic number, because the mean of its divisors is an integer number (18165840).

Almost surely, 2^131878721 is an apocalyptic number.

It is an amenable number.

131878721 is a deficient number, since it is larger than the sum of its proper divisors (13447999).

131878721 is a wasteful number, since it uses less digits than its factorization.

131878721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 235975.

The product of its digits is 18816, while the sum is 38.

The square root of 131878721 is about 11483.8460891811. The cubic root of 131878721 is about 509.0083524631.

The spelling of 131878721 in words is "one hundred thirty-one million, eight hundred seventy-eight thousand, seven hundred twenty-one".