66601905 has 32 divisors (see below), whose sum is σ = 112803840. Its totient is φ = 33485760.

The previous prime is 66601901. The next prime is 66601967. The reversal of 66601905 is 50910666.

It is not a de Polignac number, because 66601905 - 2² = 66601901 is a prime.

It is not an unprimeable number, because it can be changed into a prime (66601901) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 23136 + ... + 25854.

It is an arithmetic number, because the mean of its divisors is an integer number (3525120).

Almost surely, 2^66601905 is an apocalyptic number.

It is an amenable number.

66601905 is a deficient number, since it is larger than the sum of its proper divisors (46201935).

66601905 is a wasteful number, since it uses less digits than its factorization.

66601905 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2821.

The product of its (nonzero) digits is 9720, while the sum is 33.

The square root of 66601905 is about 8160.9990197279. Note that the first 3 decimals coincide. The cubic root of 66601905 is about 405.3487926539.

The spelling of 66601905 in words is "sixty-six million, six hundred one thousand, nine hundred five".