67731661 has 2 divisors, whose sum is σ = 67731662. Its totient is φ = 67731660.

The previous prime is 67731659. The next prime is 67731673. The reversal of 67731661 is 16613776.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 54908100 + 12823561 = 7410^2 + 3581^2 .

It is a cyclic number.

It is not a de Polignac number, because 67731661 - 2¹ = 67731659 is a prime.

Together with 67731659, it forms a pair of twin primes.

It is equal to p_3992455 and since 67731661 and 3992455 have the same sum of digits, it is a Honaker prime.

It is a self number, because there is not a number n which added to its sum of digits gives 67731661.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (67731611) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33865830 + 33865831.

It is an arithmetic number, because the mean of its divisors is an integer number (33865831).

Almost surely, 2^67731661 is an apocalyptic number.

It is an amenable number.

67731661 is a deficient number, since it is larger than the sum of its proper divisors (1).

67731661 is an equidigital number, since it uses as much as digits as its factorization.

67731661 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 31752, while the sum is 37.

The square root of 67731661 is about 8229.9247262657. The cubic root of 67731661 is about 407.6279067036.

The spelling of 67731661 in words is "sixty-seven million, seven hundred thirty-one thousand, six hundred sixty-one".