66987623 has 2 divisors, whose sum is σ = 66987624. Its totient is φ = 66987622.

The previous prime is 66987619. The next prime is 66987631. The reversal of 66987623 is 32678966.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 66987623 - 2² = 66987619 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (66987653) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33493811 + 33493812.

It is an arithmetic number, because the mean of its divisors is an integer number (33493812).

Almost surely, 2^66987623 is an apocalyptic number.

66987623 is a deficient number, since it is larger than the sum of its proper divisors (1).

66987623 is an equidigital number, since it uses as much as digits as its factorization.

66987623 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 653184, while the sum is 47.

The square root of 66987623 is about 8184.5966913465. The cubic root of 66987623 is about 406.1297986632.

The spelling of 66987623 in words is "sixty-six million, nine hundred eighty-seven thousand, six hundred twenty-three".