396666687 has 4 divisors (see below), whose sum is σ = 528888920. Its totient is φ = 264444456.

The previous prime is 396666653. The next prime is 396666689. The reversal of 396666687 is 786666693.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 396666687 - 2¹⁹ = 396142399 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (396666689) 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, 66111112 + ... + 66111117.

It is an arithmetic number, because the mean of its divisors is an integer number (132222230).

Almost surely, 2^396666687 is an apocalyptic number.

396666687 is a deficient number, since it is larger than the sum of its proper divisors (132222233).

396666687 is a wasteful number, since it uses less digits than its factorization.

396666687 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 132222232.

The product of its digits is 11757312, while the sum is 57.

The square root of 396666687 is about 19916.4928388509. The cubic root of 396666687 is about 734.7539164153.

It can be divided in two parts, 39 and 6666687, that added together give a triangular number (6666726 = T₃₆₅₁).

The spelling of 396666687 in words is "three hundred ninety-six million, six hundred sixty-six thousand, six hundred eighty-seven".