428999991 has 16 divisors (see below), whose sum is σ = 655812864. Its totient is φ = 244355904.

The previous prime is 428999971. The next prime is 429000017. The reversal of 428999991 is 199999824.

It is a happy number.

It is not a de Polignac number, because 428999991 - 2⁵ = 428999959 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (428999971) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 26061 + ... + 39206.

It is an arithmetic number, because the mean of its divisors is an integer number (40988304).

Almost surely, 2^428999991 is an apocalyptic number.

428999991 is a deficient number, since it is larger than the sum of its proper divisors (226812873).

428999991 is a wasteful number, since it uses less digits than its factorization.

428999991 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 65590.

The product of its digits is 3779136, while the sum is 60.

The square root of 428999991 is about 20712.3149599459. The cubic root of 428999991 is about 754.1986679433.

The spelling of 428999991 in words is "four hundred twenty-eight million, nine hundred ninety-nine thousand, nine hundred ninety-one".