66615433 has 2 divisors, whose sum is σ = 66615434. Its totient is φ = 66615432.

The previous prime is 66615431. The next prime is 66615473. The reversal of 66615433 is 33451666.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 63952009 + 2663424 = 7997^2 + 1632^2 .

It is a cyclic number.

It is not a de Polignac number, because 66615433 - 2¹ = 66615431 is a prime.

Together with 66615431, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (66615431) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33307716 + 33307717.

It is an arithmetic number, because the mean of its divisors is an integer number (33307717).

Almost surely, 2^66615433 is an apocalyptic number.

It is an amenable number.

66615433 is a deficient number, since it is larger than the sum of its proper divisors (1).

66615433 is an equidigital number, since it uses as much as digits as its factorization.

66615433 is an evil number, because the sum of its binary digits is even.

The product of its digits is 38880, while the sum is 34.

The square root of 66615433 is about 8161.8277977424. The cubic root of 66615433 is about 405.3762352485.

The spelling of 66615433 in words is "sixty-six million, six hundred fifteen thousand, four hundred thirty-three".