66557097 has 6 divisors (see below), whose sum is σ = 96138042. Its totient is φ = 44371392.

The previous prime is 66557087. The next prime is 66557107. The reversal of 66557097 is 79075566.

It is a happy number.

66557097 is a `hidden beast` number, since 6 + 6 + 557 + 0 + 97 = 666.

It is an interprime number because it is at equal distance from previous prime (66557087) and next prime (66557107).

It can be written as a sum of positive squares in only one way, i.e., 46090521 + 20466576 = 6789^2 + 4524^2 .

It is a de Polignac number, because none of the positive numbers 2^k-66557097 is a prime.

It is a super-2 number, since 2×66557097² = 8859694322134818, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (66557047) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 3697608 + ... + 3697625.

It is an arithmetic number, because the mean of its divisors is an integer number (16023007).

Almost surely, 2^66557097 is an apocalyptic number.

It is an amenable number.

66557097 is a deficient number, since it is larger than the sum of its proper divisors (29580945).

66557097 is a wasteful number, since it uses less digits than its factorization.

66557097 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7395239 (or 7395236 counting only the distinct ones).

The product of its (nonzero) digits is 396900, while the sum is 45.

The square root of 66557097 is about 8158.2533057021. The cubic root of 66557097 is about 405.2578696120.

The spelling of 66557097 in words is "sixty-six million, five hundred fifty-seven thousand, ninety-seven".