666724947 has 16 divisors (see below), whose sum is σ = 1022694912. Its totient is φ = 378460800.

The previous prime is 666724913. The next prime is 666724963. The reversal of 666724947 is 749427666.

It is not a de Polignac number, because 666724947 - 2¹¹ = 666722899 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 666724947.

It is not an unprimeable number, because it can be changed into a prime (666724907) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 101958 + ... + 108299.

It is an arithmetic number, because the mean of its divisors is an integer number (63918432).

Almost surely, 2^666724947 is an apocalyptic number.

666724947 is a deficient number, since it is larger than the sum of its proper divisors (355969965).

666724947 is a wasteful number, since it uses less digits than its factorization.

666724947 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 210418.

The product of its digits is 3048192, while the sum is 51.

The square root of 666724947 is about 25821.0175438537. The cubic root of 666724947 is about 873.6059202749.

The spelling of 666724947 in words is "six hundred sixty-six million, seven hundred twenty-four thousand, nine hundred forty-seven".