867885661 has 2 divisors, whose sum is σ = 867885662. Its totient is φ = 867885660.

The previous prime is 867885647. The next prime is 867885677. The reversal of 867885661 is 166588768.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 815959225 + 51926436 = 28565^2 + 7206^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-867885661 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (867885761) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 433942830 + 433942831.

It is an arithmetic number, because the mean of its divisors is an integer number (433942831).

Almost surely, 2^867885661 is an apocalyptic number.

It is an amenable number.

867885661 is a deficient number, since it is larger than the sum of its proper divisors (1).

867885661 is an equidigital number, since it uses as much as digits as its factorization.

867885661 is an evil number, because the sum of its binary digits is even.

The product of its digits is 3870720, while the sum is 55.

The square root of 867885661 is about 29459.8992021358. The cubic root of 867885661 is about 953.8662975710.

The spelling of 867885661 in words is "eight hundred sixty-seven million, eight hundred eighty-five thousand, six hundred sixty-one".