217149025551 has 32 divisors (see below), whose sum is σ = 301042065408. Its totient is φ = 139130231040.

The previous prime is 217149025529. The next prime is 217149025579. The reversal of 217149025551 is 155520941712.

It is not a de Polignac number, because 217149025551 - 2⁶ = 217149025487 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (217149020551) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 5200011 + ... + 5241603.

It is an arithmetic number, because the mean of its divisors is an integer number (9407564544).

Almost surely, 2^217149025551 is an apocalyptic number.

217149025551 is a deficient number, since it is larger than the sum of its proper divisors (83893039857).

217149025551 is a wasteful number, since it uses less digits than its factorization.

217149025551 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 42311.

The product of its (nonzero) digits is 126000, while the sum is 42.

The spelling of 217149025551 in words is "two hundred seventeen billion, one hundred forty-nine million, twenty-five thousand, five hundred fifty-one".