80821904 has 10 divisors (see below), whose sum is σ = 156592470. Its totient is φ = 40410944.

The previous prime is 80821903. The next prime is 80821907. The reversal of 80821904 is 40912808.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 42876304 + 37945600 = 6548^2 + 6160^2 .

It is not an unprimeable number, because it can be changed into a prime (80821903) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2525669 + ... + 2525700.

It is an arithmetic number, because the mean of its divisors is an integer number (15659247).

Almost surely, 2^80821904 is an apocalyptic number.

It is an amenable number.

80821904 is a deficient number, since it is larger than the sum of its proper divisors (75770566).

80821904 is a wasteful number, since it uses less digits than its factorization.

80821904 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5051377 (or 5051371 counting only the distinct ones).

The product of its (nonzero) digits is 4608, while the sum is 32.

The square root of 80821904 is about 8990.1003331442. The cubic root of 80821904 is about 432.3575286688.

The spelling of 80821904 in words is "eighty million, eight hundred twenty-one thousand, nine hundred four".