66615427 has 2 divisors, whose sum is σ = 66615428. Its totient is φ = 66615426.

The previous prime is 66615397. The next prime is 66615431. The reversal of 66615427 is 72451666.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-66615427 is a prime.

It is a super-2 number, since 2×66615427² = 8875230228784658, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (66613427) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33307713 + 33307714.

It is an arithmetic number, because the mean of its divisors is an integer number (33307714).

Almost surely, 2^66615427 is an apocalyptic number.

66615427 is a deficient number, since it is larger than the sum of its proper divisors (1).

66615427 is an equidigital number, since it uses as much as digits as its factorization.

66615427 is an evil number, because the sum of its binary digits is even.

The product of its digits is 60480, while the sum is 37.

The square root of 66615427 is about 8161.8274301776. The cubic root of 66615427 is about 405.3762230778.

The spelling of 66615427 in words is "sixty-six million, six hundred fifteen thousand, four hundred twenty-seven".