428034721 has 9 divisors (see below), whose sum is σ = 455068249. Its totient is φ = 402525184.

The previous prime is 428034637. The next prime is 428034757. The reversal of 428034721 is 127430824.

The square root of 428034721 is 20689.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in 4 ways, for example, as 6964321 + 421070400 = 2639^2 + 20520^2 .

It is not a de Polignac number, because 428034721 - 2¹¹ = 428032673 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (428034121) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 351105 + ... + 352321.

Almost surely, 2^428034721 is an apocalyptic number.

428034721 is the 20689-th square number.

428034721 is the 10345-th centered octagonal number.

It is an amenable number.

428034721 is a deficient number, since it is larger than the sum of its proper divisors (27033528).

428034721 is an frugal number, since it uses more digits than its factorization.

428034721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2468 (or 1234 counting only the distinct ones).

The product of its (nonzero) digits is 10752, while the sum is 31.

The cubic root of 428034721 is about 753.6325824248.

It can be divided in two parts, 42803 and 4721, that added together give a square (47524 = 218²).

The spelling of 428034721 in words is "four hundred twenty-eight million, thirty-four thousand, seven hundred twenty-one".