66538719 has 32 divisors (see below), whose sum is σ = 106901760. Its totient is φ = 40660704.

The previous prime is 66538711. The next prime is 66538753. The reversal of 66538719 is 91783566.

It is a happy number.

It is not a de Polignac number, because 66538719 - 2³ = 66538711 is a prime.

It is a super-2 number, since 2×66538719² = 8854802252321922, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66538711) 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 31 ways as a sum of consecutive naturals, for example, 56632 + ... + 57794.

It is an arithmetic number, because the mean of its divisors is an integer number (3340680).

Almost surely, 2^66538719 is an apocalyptic number.

66538719 is a deficient number, since it is larger than the sum of its proper divisors (40363041).

66538719 is a wasteful number, since it uses less digits than its factorization.

66538719 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1348 (or 1342 counting only the distinct ones).

The product of its digits is 272160, while the sum is 45.

The square root of 66538719 is about 8157.1268838973. The cubic root of 66538719 is about 405.2205657277.

The spelling of 66538719 in words is "sixty-six million, five hundred thirty-eight thousand, seven hundred nineteen".