216078557 has 8 divisors (see below), whose sum is σ = 223207896. Its totient is φ = 209017152.

The previous prime is 216078553. The next prime is 216078571. The reversal of 216078557 is 755870612.

216078557 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 4 ways, for example, as 138039001 + 78039556 = 11749^2 + 8834^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 216078557 - 2² = 216078553 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 (216078553) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 10478 + ... + 23279.

It is an arithmetic number, because the mean of its divisors is an integer number (27900987).

Almost surely, 2^216078557 is an apocalyptic number.

It is an amenable number.

216078557 is a deficient number, since it is larger than the sum of its proper divisors (7129339).

216078557 is a wasteful number, since it uses less digits than its factorization.

216078557 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 33967.

The product of its (nonzero) digits is 117600, while the sum is 41.

The square root of 216078557 is about 14699.6107771601. The cubic root of 216078557 is about 600.0727291467.

The spelling of 216078557 in words is "two hundred sixteen million, seventy-eight thousand, five hundred fifty-seven".