16000721 has 8 divisors (see below), whose sum is σ = 18057600. Its totient is φ = 14044240.

The previous prime is 16000711. The next prime is 16000729. The reversal of 16000721 is 12700061.

It is a happy number.

16000721 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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 16000721 - 2¹⁸ = 15738577 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 16000721.

It is not an unprimeable number, because it can be changed into a prime (16000729) 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, 24761 + ... + 25398.

It is an arithmetic number, because the mean of its divisors is an integer number (2257200).

Almost surely, 2^16000721 is an apocalyptic number.

16000721 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

16000721 is a deficient number, since it is larger than the sum of its proper divisors (2056879).

16000721 is a wasteful number, since it uses less digits than its factorization.

16000721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 50199.

The product of its (nonzero) digits is 84, while the sum is 17.

The square root of 16000721 is about 4000.0901239847. The cubic root of 16000721 is about 251.9879949349.

Adding to 16000721 its reverse (12700061), we get a palindrome (28700782).

The spelling of 16000721 in words is "sixteen million, seven hundred twenty-one", and thus it is an aban number.