66987958 has 16 divisors (see below), whose sum is σ = 105937920. Its totient is φ = 31680936.

The previous prime is 66987953. The next prime is 66987989. The reversal of 66987958 is 85978966.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66987953) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 35835 + ... + 37657.

It is an arithmetic number, because the mean of its divisors is an integer number (6621120).

Almost surely, 2^66987958 is an apocalyptic number.

66987958 is a deficient number, since it is larger than the sum of its proper divisors (38949962).

66987958 is a wasteful number, since it uses less digits than its factorization.

66987958 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2811.

The product of its digits is 6531840, while the sum is 58.

The square root of 66987958 is about 8184.6171565932. The cubic root of 66987958 is about 406.1304756701.

The spelling of 66987958 in words is "sixty-six million, nine hundred eighty-seven thousand, nine hundred fifty-eight".