217151442 has 20 divisors (see below), whose sum is σ = 486580446. Its totient is φ = 72383760.

The previous prime is 217151369. The next prime is 217151443. The reversal of 217151442 is 244151712.

217151442 is a `hidden beast` number, since 2 + 171 + 51 + 442 = 666.

It can be written as a sum of positive squares in only one way, i.e., 179586801 + 37564641 = 13401^2 + 6129^2 .

It is a Harshad number since it is a multiple of its sum of digits (27).

It is not an unprimeable number, because it can be changed into a prime (217151443) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 670059 + ... + 670382.

Almost surely, 2^217151442 is an apocalyptic number.

217151442 is an abundant number, since it is smaller than the sum of its proper divisors (269429004).

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

217151442 is a wasteful number, since it uses less digits than its factorization.

217151442 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1340455 (or 1340446 counting only the distinct ones).

The product of its digits is 2240, while the sum is 27.

The square root of 217151442 is about 14736.0592425519. The cubic root of 217151442 is about 601.0642611309.

The spelling of 217151442 in words is "two hundred seventeen million, one hundred fifty-one thousand, four hundred forty-two".