217628428 has 6 divisors (see below), whose sum is σ = 380849756. Its totient is φ = 108814212.

The previous prime is 217628423. The next prime is 217628429. The reversal of 217628428 is 824826712.

It is not an unprimeable number, because it can be changed into a prime (217628423) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 27203550 + ... + 27203557.

Almost surely, 2^217628428 is an apocalyptic number.

It is an amenable number.

217628428 is a deficient number, since it is larger than the sum of its proper divisors (163221328).

217628428 is a wasteful number, since it uses less digits than its factorization.

217628428 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 54407111 (or 54407109 counting only the distinct ones).

The product of its digits is 86016, while the sum is 40.

The square root of 217628428 is about 14752.2346781767. The cubic root of 217628428 is about 601.5040303745.

The spelling of 217628428 in words is "two hundred seventeen million, six hundred twenty-eight thousand, four hundred twenty-eight".