661774067 has 2 divisors, whose sum is σ = 661774068. Its totient is φ = 661774066.

The previous prime is 661774049. The next prime is 661774093. The reversal of 661774067 is 760477166.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 661774067 - 2¹⁴ = 661757683 is a prime.

It is not a weakly prime, because it can be changed into another prime (661774027) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 330887033 + 330887034.

It is an arithmetic number, because the mean of its divisors is an integer number (330887034).

Almost surely, 2^661774067 is an apocalyptic number.

661774067 is a deficient number, since it is larger than the sum of its proper divisors (1).

661774067 is an equidigital number, since it uses as much as digits as its factorization.

661774067 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 296352, while the sum is 44.

The square root of 661774067 is about 25724.9697181552. The cubic root of 661774067 is about 871.4381757314.

The spelling of 661774067 in words is "six hundred sixty-one million, seven hundred seventy-four thousand, sixty-seven".