217028977615 has 16 divisors (see below), whose sum is σ = 271791065088. Its totient is φ = 166054156576.

The previous prime is 217028977567. The next prime is 217028977619. The reversal of 217028977615 is 516779820712.

It is a cyclic number.

It is not a de Polignac number, because 217028977615 - 2²¹ = 217026880463 is a prime.

It is a super-2 number, since 2×217028977615² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (217028977619) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 871992 + ... + 1092898.

It is an arithmetic number, because the mean of its divisors is an integer number (16986941568).

Almost surely, 2^217028977615 is an apocalyptic number.

217028977615 is a deficient number, since it is larger than the sum of its proper divisors (54762087473).

217028977615 is a wasteful number, since it uses less digits than its factorization.

217028977615 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 229478.

The product of its (nonzero) digits is 2963520, while the sum is 55.

The spelling of 217028977615 in words is "two hundred seventeen billion, twenty-eight million, nine hundred seventy-seven thousand, six hundred fifteen".