164866861 has 4 divisors (see below), whose sum is σ = 165973500. Its totient is φ = 163760224.

The previous prime is 164866853. The next prime is 164866873. The reversal of 164866861 is 168668461.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 168668461 = 13 ⋅12974497.

It can be written as a sum of positive squares in 2 ways, for example, as 10361961 + 154504900 = 3219^2 + 12430^2 .

It is a cyclic number.

It is not a de Polignac number, because 164866861 - 2³ = 164866853 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 (164866811) 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, 553096 + ... + 553393.

It is an arithmetic number, because the mean of its divisors is an integer number (41493375).

Almost surely, 2^164866861 is an apocalyptic number.

It is an amenable number.

164866861 is a deficient number, since it is larger than the sum of its proper divisors (1106639).

164866861 is a wasteful number, since it uses less digits than its factorization.

164866861 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1106638.

The product of its digits is 331776, while the sum is 46.

The square root of 164866861 is about 12840.0491042675. The cubic root of 164866861 is about 548.3330919788. Note that the first 3 decimals are identical.

The spelling of 164866861 in words is "one hundred sixty-four million, eight hundred sixty-six thousand, eight hundred sixty-one".