217076787225 has 81 divisors (see below), whose sum is σ = 394356319383. Its totient is φ = 114145447680.

The previous prime is 217076787143. The next prime is 217076787233. The reversal of 217076787225 is 522787670712.

The square root of 217076787225 is 465915.

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

It can be written as a sum of positive squares in 13 ways, for example, as 156761356761 + 60315430464 = 395931^2 + 245592^2 .

It is not a de Polignac number, because 217076787225 - 2¹⁹ = 217076262937 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 80 ways as a sum of consecutive naturals, for example, 621996351 + ... + 621996699.

Almost surely, 2^217076787225 is an apocalyptic number.

217076787225 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

217076787225 is the 465915-th square number.

217076787225 is the 232958-th centered octagonal number.

It is an amenable number.

217076787225 is a deficient number, since it is larger than the sum of its proper divisors (177279532158).

217076787225 is an frugal number, since it uses more digits than its factorization.

217076787225 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 892 (or 446 counting only the distinct ones).

The product of its (nonzero) digits is 4609920, while the sum is 54.

The spelling of 217076787225 in words is "two hundred seventeen billion, seventy-six million, seven hundred eighty-seven thousand, two hundred twenty-five".