66987172 has 24 divisors (see below), whose sum is σ = 134414784. Its totient is φ = 28614432.

The previous prime is 66987143. The next prime is 66987199. The reversal of 66987172 is 27178966.

It is a happy number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5103 + ... + 12649.

It is an arithmetic number, because the mean of its divisors is an integer number (5600616).

Almost surely, 2^66987172 is an apocalyptic number.

It is an amenable number.

66987172 is an abundant number, since it is smaller than the sum of its proper divisors (67427612).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

66987172 is a wasteful number, since it uses less digits than its factorization.

66987172 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7875 (or 7873 counting only the distinct ones).

The product of its digits is 254016, while the sum is 46.

The square root of 66987172 is about 8184.5691395455. The cubic root of 66987172 is about 406.1288872264.

The spelling of 66987172 in words is "sixty-six million, nine hundred eighty-seven thousand, one hundred seventy-two".