217056740 has 24 divisors (see below), whose sum is σ = 462066360. Its totient is φ = 85632768.

The previous prime is 217056737. The next prime is 217056743. The reversal of 217056740 is 47650712.

It is an interprime number because it is at equal distance from previous prime (217056737) and next prime (217056743).

It can be written as a sum of positive squares in 4 ways, for example, as 33616804 + 183439936 = 5798^2 + 13544^2 .

It is a super-2 number, since 2×217056740² = 94227256758855200, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 217056697 and 217056706.

It is not an unprimeable number, because it can be changed into a prime (217056743) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 72875 + ... + 75794.

It is an arithmetic number, because the mean of its divisors is an integer number (19252765).

Almost surely, 2^217056740 is an apocalyptic number.

217056740 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

217056740 is an abundant number, since it is smaller than the sum of its proper divisors (245009620).

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

217056740 is a wasteful number, since it uses less digits than its factorization.

217056740 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 148751 (or 148749 counting only the distinct ones).

The product of its (nonzero) digits is 11760, while the sum is 32.

The square root of 217056740 is about 14732.8456178703. The cubic root of 217056740 is about 600.9768716362.

The spelling of 217056740 in words is "two hundred seventeen million, fifty-six thousand, seven hundred forty".