216512404 has 6 divisors (see below), whose sum is σ = 378896714. Its totient is φ = 108256200.

The previous prime is 216512369. The next prime is 216512447. The reversal of 216512404 is 404215612.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 205635600 + 10876804 = 14340^2 + 3298^2 .

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 27064047 + ... + 27064054.

Almost surely, 2^216512404 is an apocalyptic number.

It is an amenable number.

216512404 is a deficient number, since it is larger than the sum of its proper divisors (162384310).

216512404 is a wasteful number, since it uses less digits than its factorization.

216512404 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 54128105 (or 54128103 counting only the distinct ones).

The product of its (nonzero) digits is 1920, while the sum is 25.

The square root of 216512404 is about 14714.3604686035. The cubic root of 216512404 is about 600.4740734734.

The spelling of 216512404 in words is "two hundred sixteen million, five hundred twelve thousand, four hundred four".