66771157 has 4 divisors (see below), whose sum is σ = 67180960. Its totient is φ = 66361356.

The previous prime is 66771091. The next prime is 66771167. The reversal of 66771157 is 75117766.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 75117766 = 2 ⋅37558883.

It is a cyclic number.

It is not a de Polignac number, because 66771157 - 2²³ = 58382549 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66771167) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 204657 + ... + 204982.

It is an arithmetic number, because the mean of its divisors is an integer number (16795240).

Almost surely, 2^66771157 is an apocalyptic number.

It is an amenable number.

66771157 is a deficient number, since it is larger than the sum of its proper divisors (409803).

66771157 is a wasteful number, since it uses less digits than its factorization.

66771157 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 409802.

The product of its digits is 61740, while the sum is 40.

The square root of 66771157 is about 8171.3620039746. The cubic root of 66771157 is about 405.6918662277.

It can be divided in two parts, 667 and 71157, that added together give a square (71824 = 268²).

The spelling of 66771157 in words is "sixty-six million, seven hundred seventy-one thousand, one hundred fifty-seven".