66685619 has 48 divisors (see below), whose sum is σ = 94381056. Its totient is φ = 46267200.

The previous prime is 66685609. The next prime is 66685631. The reversal of 66685619 is 91658666.

It is not a de Polignac number, because 66685619 - 2¹⁶ = 66620083 is a prime.

It is a super-2 number, since 2×66685619² = 8893943562826322, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66685609) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 217064 + ... + 217370.

It is an arithmetic number, because the mean of its divisors is an integer number (1966272).

Almost surely, 2^66685619 is an apocalyptic number.

66685619 is a deficient number, since it is larger than the sum of its proper divisors (27695437).

66685619 is a wasteful number, since it uses less digits than its factorization.

66685619 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 376 (or 369 counting only the distinct ones).

The product of its digits is 466560, while the sum is 47.

The square root of 66685619 is about 8166.1263154570. The cubic root of 66685619 is about 405.5185533709.

The spelling of 66685619 in words is "sixty-six million, six hundred eighty-five thousand, six hundred nineteen".