216490388 has 6 divisors (see below), whose sum is σ = 378858186. Its totient is φ = 108245192.

The previous prime is 216490387. The next prime is 216490397. The reversal of 216490388 is 883094612.

216490388 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 only one way, i.e., 154206724 + 62283664 = 12418^2 + 7892^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (216490387) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 27061295 + ... + 27061302.

It is an arithmetic number, because the mean of its divisors is an integer number (63143031).

Almost surely, 2^216490388 is an apocalyptic number.

It is an amenable number.

216490388 is a deficient number, since it is larger than the sum of its proper divisors (162367798).

216490388 is a wasteful number, since it uses less digits than its factorization.

216490388 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 54122601 (or 54122599 counting only the distinct ones).

The product of its (nonzero) digits is 82944, while the sum is 41.

The square root of 216490388 is about 14713.6123368804. The cubic root of 216490388 is about 600.4537197738.

The spelling of 216490388 in words is "two hundred sixteen million, four hundred ninety thousand, three hundred eighty-eight".