217390641 has 64 divisors (see below), whose sum is σ = 344977920. Its totient is φ = 120637440.

The previous prime is 217390639. The next prime is 217390669. The reversal of 217390641 is 146093712.

It is not a de Polignac number, because 217390641 - 2¹ = 217390639 is a prime.

It is not an unprimeable number, because it can be changed into a prime (217390601) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 1586725 + ... + 1586861.

It is an arithmetic number, because the mean of its divisors is an integer number (5390280).

Almost surely, 2^217390641 is an apocalyptic number.

It is an amenable number.

217390641 is a deficient number, since it is larger than the sum of its proper divisors (127587279).

217390641 is a wasteful number, since it uses less digits than its factorization.

217390641 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 266.

The product of its (nonzero) digits is 9072, while the sum is 33.

The square root of 217390641 is about 14744.1731202533. The cubic root of 217390641 is about 601.2848770763.

The spelling of 217390641 in words is "two hundred seventeen million, three hundred ninety thousand, six hundred forty-one".