80387721 has 10 divisors (see below), whose sum is σ = 120085482. Its totient is φ = 53591760.

The previous prime is 80387701. The next prime is 80387729. The reversal of 80387721 is 12778308.

It can be written as a sum of positive squares in only one way, i.e., 77792400 + 2595321 = 8820^2 + 1611^2 .

It is not a de Polignac number, because 80387721 - 2¹³ = 80379529 is a prime.

It is not an unprimeable number, because it can be changed into a prime (80387729) 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 9 ways as a sum of consecutive naturals, for example, 496140 + ... + 496301.

Almost surely, 2^80387721 is an apocalyptic number.

80387721 is a gapful number since it is divisible by the number (81) formed by its first and last digit.

It is an amenable number.

80387721 is a deficient number, since it is larger than the sum of its proper divisors (39697761).

80387721 is an equidigital number, since it uses as much as digits as its factorization.

80387721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 992453 (or 992444 counting only the distinct ones).

The product of its (nonzero) digits is 18816, while the sum is 36.

The square root of 80387721 is about 8965.9199751057. The cubic root of 80387721 is about 431.5819161163.

The spelling of 80387721 in words is "eighty million, three hundred eighty-seven thousand, seven hundred twenty-one".