66997475 has 6 divisors (see below), whose sum is σ = 83076900. Its totient is φ = 53597960.

The previous prime is 66997471. The next prime is 66997487. The reversal of 66997475 is 57479966.

It is not a de Polignac number, because 66997475 - 2² = 66997471 is a prime.

It is not an unprimeable number, because it can be changed into a prime (66997471) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1339925 + ... + 1339974.

It is an arithmetic number, because the mean of its divisors is an integer number (13846150).

Almost surely, 2^66997475 is an apocalyptic number.

66997475 is a deficient number, since it is larger than the sum of its proper divisors (16079425).

66997475 is a wasteful number, since it uses less digits than its factorization.

66997475 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2679909 (or 2679904 counting only the distinct ones).

The product of its digits is 2857680, while the sum is 53.

The square root of 66997475 is about 8185.1985314957. The cubic root of 66997475 is about 406.1497077870.

The spelling of 66997475 in words is "sixty-six million, nine hundred ninety-seven thousand, four hundred seventy-five".