216662641 has 4 divisors (see below), whose sum is σ = 233329012. Its totient is φ = 199996272.

The previous prime is 216662629. The next prime is 216662653. The reversal of 216662641 is 146266612.

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

It is an interprime number because it is at equal distance from previous prime (216662629) and next prime (216662653).

It can be written as a sum of positive squares in 2 ways, for example, as 119443041 + 97219600 = 10929^2 + 9860^2 .

It is a cyclic number.

It is not a de Polignac number, because 216662641 - 2⁵ = 216662609 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 216662597 and 216662606.

It is not an unprimeable number, because it can be changed into a prime (216662141) 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, 8333166 + ... + 8333191.

It is an arithmetic number, because the mean of its divisors is an integer number (58332253).

Almost surely, 2^216662641 is an apocalyptic number.

It is an amenable number.

216662641 is a deficient number, since it is larger than the sum of its proper divisors (16666371).

216662641 is a wasteful number, since it uses less digits than its factorization.

216662641 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16666370.

The product of its digits is 20736, while the sum is 34.

The square root of 216662641 is about 14719.4646981471. The cubic root of 216662641 is about 600.6129301294.

The spelling of 216662641 in words is "two hundred sixteen million, six hundred sixty-two thousand, six hundred forty-one".