216161690 has 8 divisors (see below), whose sum is σ = 389091060. Its totient is φ = 86464672.

The previous prime is 216161669. The next prime is 216161711. The reversal of 216161690 is 96161612.

It is an interprime number because it is at equal distance from previous prime (216161669) and next prime (216161711).

It can be written as a sum of positive squares in 2 ways, for example, as 207907561 + 8254129 = 14419^2 + 2873^2 .

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

It is a super-2 number, since 2×216161690² = 93451752447312200, which contains 22 as substring.

It is an alternating number because its digits alternate between even and odd.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 10808075 + ... + 10808094.

Almost surely, 2^216161690 is an apocalyptic number.

216161690 is a deficient number, since it is larger than the sum of its proper divisors (172929370).

216161690 is a wasteful number, since it uses less digits than its factorization.

216161690 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21616176.

The product of its (nonzero) digits is 3888, while the sum is 32.

The square root of 216161690 is about 14702.4382331639. The cubic root of 216161690 is about 600.1496756219.

The spelling of 216161690 in words is "two hundred sixteen million, one hundred sixty-one thousand, six hundred ninety".