66121533 has 6 divisors (see below), whose sum is σ = 95508894. Its totient is φ = 44081016.

The previous prime is 66121529. The next prime is 66121547. The reversal of 66121533 is 33512166.

66121533 is a `hidden beast` number, since 6 + 6 + 121 + 533 = 666.

It can be written as a sum of positive squares in only one way, i.e., 54952569 + 11168964 = 7413^2 + 3342^2 .

It is not a de Polignac number, because 66121533 - 2² = 66121529 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 66121497 and 66121506.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66121633) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 3673410 + ... + 3673427.

It is an arithmetic number, because the mean of its divisors is an integer number (15918149).

Almost surely, 2^66121533 is an apocalyptic number.

It is an amenable number.

66121533 is a deficient number, since it is larger than the sum of its proper divisors (29387361).

66121533 is a wasteful number, since it uses less digits than its factorization.

66121533 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7346843 (or 7346840 counting only the distinct ones).

The product of its digits is 3240, while the sum is 27.

The square root of 66121533 is about 8131.5148035283. The cubic root of 66121533 is about 404.3719024995.

Adding to 66121533 its reverse (33512166), we get a palindrome (99633699).

The spelling of 66121533 in words is "sixty-six million, one hundred twenty-one thousand, five hundred thirty-three".