216615261655 has 32 divisors (see below), whose sum is σ = 312000292800. Its totient is φ = 142628677632.

The previous prime is 216615261641. The next prime is 216615261671. The reversal of 216615261655 is 556162516612.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 216615261655 - 2¹¹ = 216615259607 is a prime.

It is a super-2 number, since 2×216615261655² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 5137740 + ... + 5179729.

It is an arithmetic number, because the mean of its divisors is an integer number (9750009150).

Almost surely, 2^216615261655 is an apocalyptic number.

216615261655 is a deficient number, since it is larger than the sum of its proper divisors (95385031145).

216615261655 is a wasteful number, since it uses less digits than its factorization.

216615261655 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10317523.

The product of its digits is 648000, while the sum is 46.

The spelling of 216615261655 in words is "two hundred sixteen billion, six hundred fifteen million, two hundred sixty-one thousand, six hundred fifty-five".