66445157 has 4 divisors (see below), whose sum is σ = 66852960. Its totient is φ = 66037356.

The previous prime is 66445139. The next prime is 66445187. The reversal of 66445157 is 75154466.

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: 75154466 = 2 ⋅37577233.

It is a cyclic number.

It is not a de Polignac number, because 66445157 - 2¹² = 66441061 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 66445157.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66445117) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 203657 + ... + 203982.

It is an arithmetic number, because the mean of its divisors is an integer number (16713240).

Almost surely, 2^66445157 is an apocalyptic number.

It is an amenable number.

66445157 is a deficient number, since it is larger than the sum of its proper divisors (407803).

66445157 is a wasteful number, since it uses less digits than its factorization.

66445157 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 407802.

The product of its digits is 100800, while the sum is 38.

The square root of 66445157 is about 8151.3898814865. The cubic root of 66445157 is about 405.0305458849.

The spelling of 66445157 in words is "sixty-six million, four hundred forty-five thousand, one hundred fifty-seven".