65687381 has 2 divisors, whose sum is σ = 65687382. Its totient is φ = 65687380.

The previous prime is 65687339. The next prime is 65687443. The reversal of 65687381 is 18378656.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 62948356 + 2739025 = 7934^2 + 1655^2 .

It is a cyclic number.

It is not a de Polignac number, because 65687381 - 2⁶ = 65687317 is a prime.

It is a super-2 number, since 2×65687381² = 8629664045278322, which contains 22 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (65687311) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 32843690 + 32843691.

It is an arithmetic number, because the mean of its divisors is an integer number (32843691).

Almost surely, 2^65687381 is an apocalyptic number.

It is an amenable number.

65687381 is a deficient number, since it is larger than the sum of its proper divisors (1).

65687381 is an equidigital number, since it uses as much as digits as its factorization.

65687381 is an evil number, because the sum of its binary digits is even.

The product of its digits is 241920, while the sum is 44.

The square root of 65687381 is about 8104.7751973759. The cubic root of 65687381 is about 403.4849271169.

The spelling of 65687381 in words is "sixty-five million, six hundred eighty-seven thousand, three hundred eighty-one".