228217297787661 has 64 divisors (see below), whose sum is σ = 388279594680320. Its totient is φ = 115986468568320.

The previous prime is 228217297787651. The next prime is 228217297787693. The reversal of 228217297787661 is 166787792712822.

It is not a de Polignac number, because 228217297787661 - 2⁷ = 228217297787533 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (228217297787641) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 56940745 + ... + 60816798.

It is an arithmetic number, because the mean of its divisors is an integer number (6066868666880).

Almost surely, 2^{228217297787661} is an apocalyptic number.

228217297787661 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

228217297787661 is a deficient number, since it is larger than the sum of its proper divisors (160062296892659).

228217297787661 is a wasteful number, since it uses less digits than its factorization.

228217297787661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 117757826.

The product of its digits is 796594176, while the sum is 75.

The spelling of 228217297787661 in words is "two hundred twenty-eight trillion, two hundred seventeen billion, two hundred ninety-seven million, seven hundred eighty-seven thousand, six hundred sixty-one".