216561660010 has 16 divisors (see below), whose sum is σ = 389855761416. Its totient is φ = 86614714368.

The previous prime is 216561659999. The next prime is 216561660023. The reversal of 216561660010 is 10066165612.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 195692101641 + 20869558369 = 442371^2 + 144463^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1151967 + ... + 1326706.

Almost surely, 2^216561660010 is an apocalyptic number.

216561660010 is a deficient number, since it is larger than the sum of its proper divisors (173294101406).

216561660010 is a wasteful number, since it uses less digits than its factorization.

216561660010 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2487417.

The product of its (nonzero) digits is 12960, while the sum is 34.

The spelling of 216561660010 in words is "two hundred sixteen billion, five hundred sixty-one million, six hundred sixty thousand, ten".