66961605 has 32 divisors (see below), whose sum is σ = 115200000. Its totient is φ = 33106752.

The previous prime is 66961603. The next prime is 66961619. The reversal of 66961605 is 50616966.

It is not a de Polignac number, because 66961605 - 2¹ = 66961603 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66961603) 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, 10896 + ... + 15894.

It is an arithmetic number, because the mean of its divisors is an integer number (3600000).

Almost surely, 2^66961605 is an apocalyptic number.

It is an amenable number.

66961605 is a deficient number, since it is larger than the sum of its proper divisors (48238395).

66961605 is a wasteful number, since it uses less digits than its factorization.

66961605 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5073.

The product of its (nonzero) digits is 58320, while the sum is 39.

The square root of 66961605 is about 8183.0070878620. The cubic root of 66961605 is about 406.0772115684.

The spelling of 66961605 in words is "sixty-six million, nine hundred sixty-one thousand, six hundred five".