66533897 has 4 divisors (see below), whose sum is σ = 66918660. Its totient is φ = 66149136.

The previous prime is 66533893. The next prime is 66533899. The reversal of 66533897 is 79833566.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 79833566 = 2 ⋅39916783.

It can be written as a sum of positive squares in 2 ways, for example, as 23775376 + 42758521 = 4876^2 + 6539^2 .

It is a cyclic number.

It is not a de Polignac number, because 66533897 - 2² = 66533893 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (66533893) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 192122 + ... + 192467.

It is an arithmetic number, because the mean of its divisors is an integer number (16729665).

Almost surely, 2^66533897 is an apocalyptic number.

It is an amenable number.

66533897 is a deficient number, since it is larger than the sum of its proper divisors (384763).

66533897 is a wasteful number, since it uses less digits than its factorization.

66533897 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 384762.

The product of its digits is 816480, while the sum is 47.

The square root of 66533897 is about 8156.8313087865. The cubic root of 66533897 is about 405.2107768368.

The spelling of 66533897 in words is "sixty-six million, five hundred thirty-three thousand, eight hundred ninety-seven".