67851661 has 2 divisors, whose sum is σ = 67851662. Its totient is φ = 67851660.

The previous prime is 67851643. The next prime is 67851683. The reversal of 67851661 is 16615876.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 67404100 + 447561 = 8210^2 + 669^2 .

It is a cyclic number.

It is not a de Polignac number, because 67851661 - 2⁵ = 67851629 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (67851601) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33925830 + 33925831.

It is an arithmetic number, because the mean of its divisors is an integer number (33925831).

Almost surely, 2^67851661 is an apocalyptic number.

It is an amenable number.

67851661 is a deficient number, since it is larger than the sum of its proper divisors (1).

67851661 is an equidigital number, since it uses as much as digits as its factorization.

67851661 is an evil number, because the sum of its binary digits is even.

The product of its digits is 60480, while the sum is 40.

The square root of 67851661 is about 8237.2119676502. The cubic root of 67851661 is about 407.8684957612.

The spelling of 67851661 in words is "sixty-seven million, eight hundred fifty-one thousand, six hundred sixty-one".