217465940 has 24 divisors (see below), whose sum is σ = 457381512. Its totient is φ = 86852480.

The previous prime is 217465933. The next prime is 217465951. The reversal of 217465940 is 49564712.

It can be written as a sum of positive squares in 4 ways, for example, as 23309584 + 194156356 = 4828^2 + 13934^2 .

It is a junction number, because it is equal to n+sod(n) for n = 217465894 and 217465903.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5510 + ... + 21570.

It is an arithmetic number, because the mean of its divisors is an integer number (19057563).

Almost surely, 2^217465940 is an apocalyptic number.

217465940 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

217465940 is an abundant number, since it is smaller than the sum of its proper divisors (239915572).

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

217465940 is a wasteful number, since it uses less digits than its factorization.

217465940 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16747 (or 16745 counting only the distinct ones).

The product of its (nonzero) digits is 60480, while the sum is 38.

The square root of 217465940 is about 14746.7264163949. The cubic root of 217465940 is about 601.3542927040.

The spelling of 217465940 in words is "two hundred seventeen million, four hundred sixty-five thousand, nine hundred forty".