168192721 has 8 divisors (see below), whose sum is σ = 181558080. Its totient is φ = 155331792.

The previous prime is 168192671. The next prime is 168192749. The reversal of 168192721 is 127291861.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-168192721 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (168192751) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 125415 + ... + 126748.

It is an arithmetic number, because the mean of its divisors is an integer number (22694760).

Almost surely, 2^168192721 is an apocalyptic number.

It is an amenable number.

168192721 is a deficient number, since it is larger than the sum of its proper divisors (13365359).

168192721 is a wasteful number, since it uses less digits than its factorization.

168192721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 252215.

The product of its digits is 12096, while the sum is 37.

The square root of 168192721 is about 12968.9136399314. The cubic root of 168192721 is about 551.9957477531.

The spelling of 168192721 in words is "one hundred sixty-eight million, one hundred ninety-two thousand, seven hundred twenty-one".