66031521 has 16 divisors (see below), whose sum is σ = 91392960. Its totient is φ = 42356160.

The previous prime is 66031507. The next prime is 66031523. The reversal of 66031521 is 12513066.

It is not a de Polignac number, because 66031521 - 2¹³ = 66023329 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 66031491 and 66031500.

It is not an unprimeable number, because it can be changed into a prime (66031523) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 27651 + ... + 29943.

It is an arithmetic number, because the mean of its divisors is an integer number (5712060).

Almost surely, 2^66031521 is an apocalyptic number.

It is an amenable number.

66031521 is a deficient number, since it is larger than the sum of its proper divisors (25361439).

66031521 is a wasteful number, since it uses less digits than its factorization.

66031521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2656.

The product of its (nonzero) digits is 1080, while the sum is 24.

The square root of 66031521 is about 8125.9781565052. The cubic root of 66031521 is about 404.1883271395.

Adding to 66031521 its reverse (12513066), we get a palindrome (78544587).

The spelling of 66031521 in words is "sixty-six million, thirty-one thousand, five hundred twenty-one".