80421865 has 4 divisors (see below), whose sum is σ = 96506244. Its totient is φ = 64337488.

The previous prime is 80421863. The next prime is 80421871. The reversal of 80421865 is 56812408.

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 52838361 + 27583504 = 7269^2 + 5252^2 .

It is a cyclic number.

It is not a de Polignac number, because 80421865 - 2¹ = 80421863 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 80421865.

It is not an unprimeable number, because it can be changed into a prime (80421863) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 8042182 + ... + 8042191.

It is an arithmetic number, because the mean of its divisors is an integer number (24126561).

Almost surely, 2^80421865 is an apocalyptic number.

It is an amenable number.

80421865 is a deficient number, since it is larger than the sum of its proper divisors (16084379).

80421865 is a wasteful number, since it uses less digits than its factorization.

80421865 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16084378.

The product of its (nonzero) digits is 15360, while the sum is 34.

The square root of 80421865 is about 8967.8238720439. The cubic root of 80421865 is about 431.6430110486.

The spelling of 80421865 in words is "eighty million, four hundred twenty-one thousand, eight hundred sixty-five".