217097451081 has 48 divisors (see below), whose sum is σ = 361610016768. Its totient is φ = 122941260000.

The previous prime is 217097451031. The next prime is 217097451101. The reversal of 217097451081 is 180154790712.

It is a happy number.

It is not a de Polignac number, because 217097451081 - 2⁷ = 217097450953 is a prime.

It is a super-2 number, since 2×217097451081² (a number of 23 digits) contains 22 as substring.

It is a hoax number, since the sum of its digits (45) coincides with the sum of the digits of its distinct prime factors.

It is not an unprimeable number, because it can be changed into a prime (217097451031) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 6180490 + ... + 6215516.

It is an arithmetic number, because the mean of its divisors is an integer number (7533542016).

Almost surely, 2^217097451081 is an apocalyptic number.

217097451081 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

217097451081 is a deficient number, since it is larger than the sum of its proper divisors (144512565687).

217097451081 is a wasteful number, since it uses less digits than its factorization.

217097451081 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 35922 (or 35919 counting only the distinct ones).

The product of its (nonzero) digits is 141120, while the sum is 45.

The spelling of 217097451081 in words is "two hundred seventeen billion, ninety-seven million, four hundred fifty-one thousand, eighty-one".