428975021 has 2 divisors, whose sum is σ = 428975022. Its totient is φ = 428975020.

The previous prime is 428975011. The next prime is 428975033. The reversal of 428975021 is 120579824.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 360582121 + 68392900 = 18989^2 + 8270^2 .

It is a cyclic number.

It is not a de Polignac number, because 428975021 - 2¹⁸ = 428712877 is a prime.

It is a Chen prime.

It is equal to p_22796534 and since 428975021 and 22796534 have the same sum of digits, it is a Honaker prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (428975011) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 214487510 + 214487511.

It is an arithmetic number, because the mean of its divisors is an integer number (214487511).

Almost surely, 2^428975021 is an apocalyptic number.

It is an amenable number.

428975021 is a deficient number, since it is larger than the sum of its proper divisors (1).

428975021 is an equidigital number, since it uses as much as digits as its factorization.

428975021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 40320, while the sum is 38.

The square root of 428975021 is about 20711.7121696880. The cubic root of 428975021 is about 754.1840349157.

The spelling of 428975021 in words is "four hundred twenty-eight million, nine hundred seventy-five thousand, twenty-one".