171221248826721 has 16 divisors (see below), whose sum is σ = 253665480868800. Its totient is φ = 114145532044704.

The previous prime is 171221248826701. The next prime is 171221248826737. The reversal of 171221248826721 is 127628842122171.

It is a happy number.

171221248826721 is a `hidden beast` number, since 1 + 7 + 122 + 12 + 488 + 2 + 6 + 7 + 21 = 666.

It is not a de Polignac number, because 171221248826721 - 2⁶ = 171221248826657 is a prime.

It is a super-2 number, since 2×171221248826721² (a number of 29 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (171221248826701) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 53047131 + ... + 56182208.

It is an arithmetic number, because the mean of its divisors is an integer number (15854092554300).

Almost surely, 2^{171221248826721} is an apocalyptic number.

It is an amenable number.

171221248826721 is a deficient number, since it is larger than the sum of its proper divisors (82444232042079).

171221248826721 is a wasteful number, since it uses less digits than its factorization.

171221248826721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 109287405 (or 109287399 counting only the distinct ones).

The product of its digits is 2408448, while the sum is 54.

The spelling of 171221248826721 in words is "one hundred seventy-one trillion, two hundred twenty-one billion, two hundred forty-eight million, eight hundred twenty-six thousand, seven hundred twenty-one".