168623240721 has 16 divisors (see below), whose sum is σ = 242168204544. Its totient is φ = 103749922944.

The previous prime is 168623240717. The next prime is 168623240759. The reversal of 168623240721 is 127042326861.

It is not a de Polignac number, because 168623240721 - 2² = 168623240717 is a prime.

It is a super-2 number, since 2×168623240721² (a number of 23 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (168623240701) 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, 153081 + ... + 600566.

It is an arithmetic number, because the mean of its divisors is an integer number (15135512784).

Almost surely, 2^168623240721 is an apocalyptic number.

It is an amenable number.

168623240721 is a deficient number, since it is larger than the sum of its proper divisors (73544963823).

168623240721 is a wasteful number, since it uses less digits than its factorization.

168623240721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 759400.

The product of its (nonzero) digits is 193536, while the sum is 42.

The spelling of 168623240721 in words is "one hundred sixty-eight billion, six hundred twenty-three million, two hundred forty thousand, seven hundred twenty-one".