67661897 has 2 divisors, whose sum is σ = 67661898. Its totient is φ = 67661896.

The previous prime is 67661861. The next prime is 67661899. The reversal of 67661897 is 79816676.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 67059721 + 602176 = 8189^2 + 776^2 .

It is a cyclic number.

It is not a de Polignac number, because 67661897 - 2¹² = 67657801 is a prime.

Together with 67661899, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (67661899) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33830948 + 33830949.

It is an arithmetic number, because the mean of its divisors is an integer number (33830949).

Almost surely, 2^67661897 is an apocalyptic number.

It is an amenable number.

67661897 is a deficient number, since it is larger than the sum of its proper divisors (1).

67661897 is an equidigital number, since it uses as much as digits as its factorization.

67661897 is an evil number, because the sum of its binary digits is even.

The product of its digits is 762048, while the sum is 50.

The square root of 67661897 is about 8225.6851994226. The cubic root of 67661897 is about 407.4879055966.

The spelling of 67661897 in words is "sixty-seven million, six hundred sixty-one thousand, eight hundred ninety-seven".