477728021 has 2 divisors, whose sum is σ = 477728022. Its totient is φ = 477728020.

The previous prime is 477727981. The next prime is 477728047. The reversal of 477728021 is 120827774.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 399600100 + 78127921 = 19990^2 + 8839^2 .

It is a cyclic number.

It is not a de Polignac number, because 477728021 - 2²² = 473533717 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (477728071) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 238864010 + 238864011.

It is an arithmetic number, because the mean of its divisors is an integer number (238864011).

Almost surely, 2^477728021 is an apocalyptic number.

It is an amenable number.

477728021 is a deficient number, since it is larger than the sum of its proper divisors (1).

477728021 is an equidigital number, since it uses as much as digits as its factorization.

477728021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 43904, while the sum is 38.

The square root of 477728021 is about 21856.9902090841. The cubic root of 477728021 is about 781.7362271924.

The spelling of 477728021 in words is "four hundred seventy-seven million, seven hundred twenty-eight thousand, twenty-one".