217120715 has 16 divisors (see below), whose sum is σ = 303844800. Its totient is φ = 148881600.

The previous prime is 217120711. The next prime is 217120723. The reversal of 217120715 is 517021712.

It is not a de Polignac number, because 217120715 - 2² = 217120711 is a prime.

It is a super-2 number, since 2×217120715² = 94282809764222450, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (217120711) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 61586 + ... + 65015.

It is an arithmetic number, because the mean of its divisors is an integer number (18990300).

Almost surely, 2^217120715 is an apocalyptic number.

217120715 is a deficient number, since it is larger than the sum of its proper divisors (86724085).

217120715 is an equidigital number, since it uses as much as digits as its factorization.

217120715 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 126627 (or 126613 counting only the distinct ones).

The product of its (nonzero) digits is 980, while the sum is 26.

The square root of 217120715 is about 14735.0166270690. The cubic root of 217120715 is about 601.0359095305.

The spelling of 217120715 in words is "two hundred seventeen million, one hundred twenty thousand, seven hundred fifteen".