66101521 has 4 divisors (see below), whose sum is σ = 66240000. Its totient is φ = 65963044.

The previous prime is 66101509. The next prime is 66101543. The reversal of 66101521 is 12510166.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-66101521 is a prime.

It is a super-2 number, since 2×66101521² = 8738822157026882, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 66101492 and 66101501.

It is not an unprimeable number, because it can be changed into a prime (66101561) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 68521 + ... + 69478.

It is an arithmetic number, because the mean of its divisors is an integer number (16560000).

Almost surely, 2^66101521 is an apocalyptic number.

It is an amenable number.

66101521 is a deficient number, since it is larger than the sum of its proper divisors (138479).

66101521 is a wasteful number, since it uses less digits than its factorization.

66101521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 138478.

The product of its (nonzero) digits is 360, while the sum is 22.

The square root of 66101521 is about 8130.2841893749. The cubic root of 66101521 is about 404.3311033494.

Adding to 66101521 its reverse (12510166), we get a palindrome (78611687).

The spelling of 66101521 in words is "sixty-six million, one hundred one thousand, five hundred twenty-one".