215661702212116 has 12 divisors (see below), whose sum is σ = 377408107666240. Its totient is φ = 107830814307480.

The previous prime is 215661702212069. The next prime is 215661702212123. The reversal of 215661702212116 is 611212207166512.

It is a happy number.

It is a congruent number.

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, 7258021 + ... + 22000051.

Almost surely, 2^{215661702212116} is an apocalyptic number.

It is an amenable number.

215661702212116 is a deficient number, since it is larger than the sum of its proper divisors (161746405454124).

215661702212116 is a wasteful number, since it uses less digits than its factorization.

215661702212116 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18399294 (or 18399292 counting only the distinct ones).

The product of its (nonzero) digits is 120960, while the sum is 43.

Adding to 215661702212116 its reverse (611212207166512), we get a palindrome (826873909378628).

The spelling of 215661702212116 in words is "two hundred fifteen trillion, six hundred sixty-one billion, seven hundred two million, two hundred twelve thousand, one hundred sixteen".