217149476049 has 81 divisors (see below), whose sum is σ = 358695091209. Its totient is φ = 131354106840.

The previous prime is 217149475997. The next prime is 217149476053. The reversal of 217149476049 is 940674941712.

The square root of 217149476049 is 465993.

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

217149476049 is a `hidden beast` number, since 2 + 17 + 14 + 9 + 4 + 7 + 604 + 9 = 666.

It is a tau number, because it is divible by the number of its divisors (81).

It is not a de Polignac number, because 217149476049 - 2²¹ = 217147378897 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 217149475986 and 217149476004.

It is not an unprimeable number, because it can be changed into a prime (217149476059) by changing a digit.

It is a polite number, since it can be written in 80 ways as a sum of consecutive naturals, for example, 415199502 + ... + 415200024.

Almost surely, 2^217149476049 is an apocalyptic number.

217149476049 is the 465993-rd square number.

217149476049 is the 232997-th centered octagonal number.

It is an amenable number.

217149476049 is a deficient number, since it is larger than the sum of its proper divisors (141545615160).

217149476049 is an frugal number, since it uses more digits than its factorization.

217149476049 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1092 (or 537 counting only the distinct ones).

The product of its (nonzero) digits is 3048192, while the sum is 54.

The spelling of 217149476049 in words is "two hundred seventeen billion, one hundred forty-nine million, four hundred seventy-six thousand, forty-nine".