66672791 has 8 divisors (see below), whose sum is σ = 69672960. Its totient is φ = 63681112.

The previous prime is 66672787. The next prime is 66672797. The reversal of 66672791 is 19727666.

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

It is not a de Polignac number, because 66672791 - 2² = 66672787 is a prime.

It is a super-2 number, since 2×66672791² = 8890522119459362, 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 (66672797) 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, 18170 + ... + 21528.

It is an arithmetic number, because the mean of its divisors is an integer number (8709120).

Almost surely, 2^66672791 is an apocalyptic number.

66672791 is a deficient number, since it is larger than the sum of its proper divisors (3000169).

66672791 is a wasteful number, since it uses less digits than its factorization.

66672791 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4245.

The product of its digits is 190512, while the sum is 44.

The square root of 66672791 is about 8165.3408379565. The cubic root of 66672791 is about 405.4925491355.

The spelling of 66672791 in words is "sixty-six million, six hundred seventy-two thousand, seven hundred ninety-one".