65139666 has 16 divisors (see below), whose sum is σ = 130370688. Its totient is φ = 21698000.

The previous prime is 65139661. The next prime is 65139667. The reversal of 65139666 is 66693156.

It is not an unprimeable number, because it can be changed into a prime (65139661) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 8551 + ... + 14261.

It is an arithmetic number, because the mean of its divisors is an integer number (8148168).

Almost surely, 2^65139666 is an apocalyptic number.

65139666 is an abundant number, since it is smaller than the sum of its proper divisors (65231022).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

65139666 is a wasteful number, since it uses less digits than its factorization.

65139666 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7617.

The product of its digits is 174960, while the sum is 42.

The square root of 65139666 is about 8070.9148180364. The cubic root of 65139666 is about 402.3603486562.

The spelling of 65139666 in words is "sixty-five million, one hundred thirty-nine thousand, six hundred sixty-six".