80005921 has 4 divisors (see below), whose sum is σ = 80714052. Its totient is φ = 79297792.

The previous prime is 80005897. The next prime is 80005931. The reversal of 80005921 is 12950008.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 39237696 + 40768225 = 6264^2 + 6385^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-80005921 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (80005931) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 353896 + ... + 354121.

It is an arithmetic number, because the mean of its divisors is an integer number (20178513).

Almost surely, 2^80005921 is an apocalyptic number.

It is an amenable number.

80005921 is a deficient number, since it is larger than the sum of its proper divisors (708131).

80005921 is a wasteful number, since it uses less digits than its factorization.

80005921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 708130.

The product of its (nonzero) digits is 720, while the sum is 25.

The square root of 80005921 is about 8944.6028978373. The cubic root of 80005921 is about 430.8975680840.

Adding to 80005921 its reverse (12950008), we get a palindrome (92955929).

The spelling of 80005921 in words is "eighty million, five thousand, nine hundred twenty-one".