66131505 has 32 divisors (see below), whose sum is σ = 128257920. Its totient is φ = 32063040.

The previous prime is 66131501. The next prime is 66131531. The reversal of 66131505 is 50513166.

It is a happy number.

66131505 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 66131505 - 2² = 66131501 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (66131501) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 20782 + ... + 23751.

It is an arithmetic number, because the mean of its divisors is an integer number (4008060).

Almost surely, 2^66131505 is an apocalyptic number.

It is an amenable number.

66131505 is a deficient number, since it is larger than the sum of its proper divisors (62126415).

66131505 is a wasteful number, since it uses less digits than its factorization.

66131505 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 44558 (or 44552 counting only the distinct ones).

The product of its (nonzero) digits is 2700, while the sum is 27.

The square root of 66131505 is about 8132.1279502969. The cubic root of 66131505 is about 404.3922296845.

It can be divided in two parts, 6613 and 1505, that added together give a palindrome (8118).

The spelling of 66131505 in words is "sixty-six million, one hundred thirty-one thousand, five hundred five".