80542721 has 6 divisors (see below), whose sum is σ = 93692610. Its totient is φ = 69036576.

The previous prime is 80542717. The next prime is 80542739. The reversal of 80542721 is 12724508.

It can be written as a sum of positive squares in only one way, i.e., 80281600 + 261121 = 8960^2 + 511^2 .

It is not a de Polignac number, because 80542721 - 2² = 80542717 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (80542771) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 821816 + ... + 821913.

It is an arithmetic number, because the mean of its divisors is an integer number (15615435).

Almost surely, 2^80542721 is an apocalyptic number.

It is an amenable number.

80542721 is a deficient number, since it is larger than the sum of its proper divisors (13149889).

80542721 is a wasteful number, since it uses less digits than its factorization.

80542721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1643743 (or 1643736 counting only the distinct ones).

The product of its (nonzero) digits is 4480, while the sum is 29.

The square root of 80542721 is about 8974.5596549357. The cubic root of 80542721 is about 431.8591236608.

The spelling of 80542721 in words is "eighty million, five hundred forty-two thousand, seven hundred twenty-one".