216161777 has 4 divisors (see below), whose sum is σ = 232789620. Its totient is φ = 199533936.

The previous prime is 216161713. The next prime is 216161801. The reversal of 216161777 is 777161612.

It is a happy number.

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

It can be written as a sum of positive squares in 2 ways, for example, as 85082176 + 131079601 = 9224^2 + 11449^2 .

It is a cyclic number.

It is not a de Polignac number, because 216161777 - 2⁶ = 216161713 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 216161777.

It is not an unprimeable number, because it can be changed into a prime (216161377) 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, 8313902 + ... + 8313927.

It is an arithmetic number, because the mean of its divisors is an integer number (58197405).

Almost surely, 2^216161777 is an apocalyptic number.

It is an amenable number.

216161777 is a deficient number, since it is larger than the sum of its proper divisors (16627843).

216161777 is a wasteful number, since it uses less digits than its factorization.

216161777 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16627842.

The product of its digits is 24696, while the sum is 38.

The square root of 216161777 is about 14702.4411918565. The cubic root of 216161777 is about 600.1497561372.

The spelling of 216161777 in words is "two hundred sixteen million, one hundred sixty-one thousand, seven hundred seventy-seven".