66187553 has 2 divisors, whose sum is σ = 66187554. Its totient is φ = 66187552.

The previous prime is 66187519. The next prime is 66187559. The reversal of 66187553 is 35578166.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 49801249 + 16386304 = 7057^2 + 4048^2 .

It is a cyclic number.

It is not a de Polignac number, because 66187553 - 2¹⁰ = 66186529 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 66187553.

It is not a weakly prime, because it can be changed into another prime (66187559) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33093776 + 33093777.

It is an arithmetic number, because the mean of its divisors is an integer number (33093777).

Almost surely, 2^66187553 is an apocalyptic number.

It is an amenable number.

66187553 is a deficient number, since it is larger than the sum of its proper divisors (1).

66187553 is an equidigital number, since it uses as much as digits as its factorization.

66187553 is an evil number, because the sum of its binary digits is even.

The product of its digits is 151200, while the sum is 41.

The square root of 66187553 is about 8135.5733049368. The cubic root of 66187553 is about 404.5064413882.

The spelling of 66187553 in words is "sixty-six million, one hundred eighty-seven thousand, five hundred fifty-three".