66849639 has 24 divisors (see below), whose sum is σ = 94077648. Its totient is φ = 42197760.

The previous prime is 66849617. The next prime is 66849647. The reversal of 66849639 is 93694866.

It is not a de Polignac number, because 66849639 - 2⁷ = 66849511 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 66849591 and 66849600.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66849659) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 168189 + ... + 168585.

It is an arithmetic number, because the mean of its divisors is an integer number (3919902).

Almost surely, 2^66849639 is an apocalyptic number.

66849639 is a deficient number, since it is larger than the sum of its proper divisors (27228009).

66849639 is a wasteful number, since it uses less digits than its factorization.

66849639 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 515 (or 478 counting only the distinct ones).

The product of its digits is 1679616, while the sum is 51.

The square root of 66849639 is about 8176.1628530748. The cubic root of 66849639 is about 405.8507524096.

The spelling of 66849639 in words is "sixty-six million, eight hundred forty-nine thousand, six hundred thirty-nine".