216605201551 has 4 divisors (see below), whose sum is σ = 218258676504. Its totient is φ = 214951726600.

The previous prime is 216605201513. The next prime is 216605201581. The reversal of 216605201551 is 155102506612.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 216605201551 - 2¹⁵ = 216605168783 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (216605201581) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 826737280 + ... + 826737541.

It is an arithmetic number, because the mean of its divisors is an integer number (54564669126).

Almost surely, 2^216605201551 is an apocalyptic number.

216605201551 is a deficient number, since it is larger than the sum of its proper divisors (1653474953).

216605201551 is a wasteful number, since it uses less digits than its factorization.

216605201551 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1653474952.

The product of its (nonzero) digits is 18000, while the sum is 34.

The spelling of 216605201551 in words is "two hundred sixteen billion, six hundred five million, two hundred one thousand, five hundred fifty-one".