66491157 has 8 divisors (see below), whose sum is σ = 88755840. Its totient is φ = 44276960.

The previous prime is 66491153. The next prime is 66491197. The reversal of 66491157 is 75119466.

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 66491157 - 2² = 66491153 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66491153) 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, 9432 + ... + 14897.

It is an arithmetic number, because the mean of its divisors is an integer number (11094480).

Almost surely, 2^66491157 is an apocalyptic number.

It is an amenable number.

66491157 is a deficient number, since it is larger than the sum of its proper divisors (22264683).

66491157 is a wasteful number, since it uses less digits than its factorization.

66491157 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 25243.

The product of its digits is 45360, while the sum is 39.

The square root of 66491157 is about 8154.2109980059. The cubic root of 66491157 is about 405.1239919091.

The spelling of 66491157 in words is "sixty-six million, four hundred ninety-one thousand, one hundred fifty-seven".