664198547 has 2 divisors, whose sum is σ = 664198548. Its totient is φ = 664198546.

The previous prime is 664198543. The next prime is 664198559. The reversal of 664198547 is 745891466.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 664198547 - 2² = 664198543 is a prime.

It is a super-2 number, since 2×664198547² = 882319419673822418, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 664198495 and 664198504.

It is not a weakly prime, because it can be changed into another prime (664198543) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 332099273 + 332099274.

It is an arithmetic number, because the mean of its divisors is an integer number (332099274).

Almost surely, 2^664198547 is an apocalyptic number.

664198547 is a deficient number, since it is larger than the sum of its proper divisors (1).

664198547 is an equidigital number, since it uses as much as digits as its factorization.

664198547 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1451520, while the sum is 50.

The square root of 664198547 is about 25772.0497244592. The cubic root of 664198547 is about 872.5010810516.

The spelling of 664198547 in words is "six hundred sixty-four million, one hundred ninety-eight thousand, five hundred forty-seven".