721602121 has 8 divisors (see below), whose sum is σ = 768117600. Its totient is φ = 675940320.

The previous prime is 721602113. The next prime is 721602149. The reversal of 721602121 is 121206127.

It is a happy number.

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

It is a cyclic number.

It is not a de Polignac number, because 721602121 - 2³ = 721602113 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 721602092 and 721602101.

It is not an unprimeable number, because it can be changed into a prime (721602151) 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, 211675 + ... + 215056.

It is an arithmetic number, because the mean of its divisors is an integer number (96014700).

Almost surely, 2^721602121 is an apocalyptic number.

It is an amenable number.

721602121 is a deficient number, since it is larger than the sum of its proper divisors (46515479).

721602121 is a wasteful number, since it uses less digits than its factorization.

721602121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 426839.

The product of its (nonzero) digits is 336, while the sum is 22.

The square root of 721602121 is about 26862.6529032410. The cubic root of 721602121 is about 896.9452487413.

Adding to 721602121 its reverse (121206127), we get a palindrome (842808248).

The spelling of 721602121 in words is "seven hundred twenty-one million, six hundred two thousand, one hundred twenty-one".