66651541 has 16 divisors (see below), whose sum is σ = 77264640. Its totient is φ = 56911680.

The previous prime is 66651521. The next prime is 66651547. The reversal of 66651541 is 14515666.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 66651541 - 2¹⁹ = 66127253 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 66651497 and 66651506.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66651547) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 8980 + ... + 14626.

It is an arithmetic number, because the mean of its divisors is an integer number (4829040).

Almost surely, 2^66651541 is an apocalyptic number.

It is an amenable number.

66651541 is a deficient number, since it is larger than the sum of its proper divisors (10613099).

66651541 is a wasteful number, since it uses less digits than its factorization.

66651541 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5724.

The product of its digits is 21600, while the sum is 34.

The square root of 66651541 is about 8164.0395025992. The cubic root of 66651541 is about 405.4494649321.

The spelling of 66651541 in words is "sixty-six million, six hundred fifty-one thousand, five hundred forty-one".