217650540 has 48 divisors (see below), whose sum is σ = 615720672. Its totient is φ = 57440256.

The previous prime is 217650533. The next prime is 217650581. The reversal of 217650540 is 45056712.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a junction number, because it is equal to n+sod(n) for n = 217650498 and 217650507.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 12879 + ... + 24518.

It is an arithmetic number, because the mean of its divisors is an integer number (12827514).

Almost surely, 2^217650540 is an apocalyptic number.

217650540 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

217650540 is an abundant number, since it is smaller than the sum of its proper divisors (398070132).

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

217650540 is a wasteful number, since it uses less digits than its factorization.

217650540 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 37506 (or 37504 counting only the distinct ones).

The product of its (nonzero) digits is 8400, while the sum is 30.

The square root of 217650540 is about 14752.9841049192. The cubic root of 217650540 is about 601.5244014979.

The spelling of 217650540 in words is "two hundred seventeen million, six hundred fifty thousand, five hundred forty".