217728894 has 32 divisors (see below), whose sum is σ = 464468256. Its totient is φ = 67804160.

The previous prime is 217728893. The next prime is 217728899. The reversal of 217728894 is 498827712.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (217728893) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 6184 + ... + 21764.

It is an arithmetic number, because the mean of its divisors is an integer number (14514633).

Almost surely, 2^217728894 is an apocalyptic number.

217728894 is an abundant number, since it is smaller than the sum of its proper divisors (246739362).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

217728894 is a wasteful number, since it uses less digits than its factorization.

217728894 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15740.

The product of its digits is 451584, while the sum is 48.

The square root of 217728894 is about 14755.6393965155. The cubic root of 217728894 is about 601.5965755868.

The spelling of 217728894 in words is "two hundred seventeen million, seven hundred twenty-eight thousand, eight hundred ninety-four".