66625987 has 2 divisors, whose sum is σ = 66625988. Its totient is φ = 66625986.

The previous prime is 66625973. The next prime is 66626017. The reversal of 66625987 is 78952666.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-66625987 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 66625987.

It is not a weakly prime, because it can be changed into another prime (66625387) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33312993 + 33312994.

It is an arithmetic number, because the mean of its divisors is an integer number (33312994).

Almost surely, 2^66625987 is an apocalyptic number.

66625987 is a deficient number, since it is larger than the sum of its proper divisors (1).

66625987 is an equidigital number, since it uses as much as digits as its factorization.

66625987 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1088640, while the sum is 49.

The square root of 66625987 is about 8162.4743184895. The cubic root of 66625987 is about 405.3976422742.

The spelling of 66625987 in words is "sixty-six million, six hundred twenty-five thousand, nine hundred eighty-seven".