66161601 has 24 divisors (see below), whose sum is σ = 104884416. Its totient is φ = 39855840.

The previous prime is 66161581. The next prime is 66161609. The reversal of 66161601 is 10616166.

It is not a de Polignac number, because 66161601 - 2⁹ = 66161089 is a prime.

It is not an unprimeable number, because it can be changed into a prime (66161609) 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, 15196 + ... + 19058.

It is an arithmetic number, because the mean of its divisors is an integer number (4370184).

Almost surely, 2^66161601 is an apocalyptic number.

It is an amenable number.

66161601 is a deficient number, since it is larger than the sum of its proper divisors (38722815).

66161601 is a wasteful number, since it uses less digits than its factorization.

66161601 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4053 (or 4050 counting only the distinct ones).

The product of its (nonzero) digits is 1296, while the sum is 27.

The square root of 66161601 is about 8133.9781779889. The cubic root of 66161601 is about 404.4535657692.

Adding to 66161601 its reverse (10616166), we get a palindrome (76777767).

The spelling of 66161601 in words is "sixty-six million, one hundred sixty-one thousand, six hundred one".