166684637 has 4 divisors (see below), whose sum is σ = 190496736. Its totient is φ = 142872540.

The previous prime is 166684631. The next prime is 166684673. The reversal of 166684637 is 736486661.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 736486661 = 739 ⋅996599.

It is a cyclic number.

It is not a de Polignac number, because 166684637 - 2¹² = 166680541 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 166684591 and 166684600.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (166684631) 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, 11906039 + ... + 11906052.

It is an arithmetic number, because the mean of its divisors is an integer number (47624184).

Almost surely, 2^166684637 is an apocalyptic number.

It is an amenable number.

166684637 is a deficient number, since it is larger than the sum of its proper divisors (23812099).

166684637 is an equidigital number, since it uses as much as digits as its factorization.

166684637 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23812098.

The product of its digits is 870912, while the sum is 47.

The square root of 166684637 is about 12910.6404566156. The cubic root of 166684637 is about 550.3409863494.

The spelling of 166684637 in words is "one hundred sixty-six million, six hundred eighty-four thousand, six hundred thirty-seven".