2018072721 has 16 divisors (see below), whose sum is σ = 3075913728. Its totient is φ = 1152901200.

The previous prime is 2018072621. The next prime is 2018072753. The reversal of 2018072721 is 1272708102.

It is a happy number.

It is not a de Polignac number, because 2018072721 - 2¹¹ = 2018070673 is a prime.

It is not an unprimeable number, because it can be changed into a prime (2018072621) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 100666 + ... + 119036.

It is an arithmetic number, because the mean of its divisors is an integer number (192244608).

Almost surely, 2^2018072721 is an apocalyptic number.

2018072721 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

2018072721 is a deficient number, since it is larger than the sum of its proper divisors (1057841007).

2018072721 is a wasteful number, since it uses less digits than its factorization.

2018072721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23612.

The product of its (nonzero) digits is 3136, while the sum is 30.

The square root of 2018072721 is about 44922.9642944452. The cubic root of 2018072721 is about 1263.7047094434.

The spelling of 2018072721 in words is "two billion, eighteen million, seventy-two thousand, seven hundred twenty-one".