216917076891025 has 27 divisors (see below), whose sum is σ = 312892559778171. Its totient is φ = 148742784965040.

The previous prime is 216917076890981. The next prime is 216917076891061. The reversal of 216917076891025 is 520198670719612.

The square root of 216917076891025 is 14728105.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 78090147680769 + 138826929210256 = 8836863^2 + 11782484^2 .

It is not a de Polignac number, because 216917076891025 - 2⁷ = 216917076890897 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 515273274 + ... + 515694076.

Almost surely, 2^{216917076891025} is an apocalyptic number.

216917076891025 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

216917076891025 is the 14728105-th square number.

216917076891025 is the 7364053-rd centered octagonal number.

It is an amenable number.

216917076891025 is a deficient number, since it is larger than the sum of its proper divisors (95975482887146).

216917076891025 is an frugal number, since it uses more digits than its factorization.

216917076891025 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 841630 (or 420815 counting only the distinct ones).

The product of its (nonzero) digits is 22861440, while the sum is 64.

The spelling of 216917076891025 in words is "two hundred sixteen trillion, nine hundred seventeen billion, seventy-six million, eight hundred ninety-one thousand, twenty-five".