428020551 has 64 divisors (see below), whose sum is σ = 753141760. Its totient is φ = 235146240.

The previous prime is 428020519. The next prime is 428020573. The reversal of 428020551 is 155020824.

It is a happy number.

It is not a de Polignac number, because 428020551 - 2⁵ = 428020519 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (428020051) 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 63 ways as a sum of consecutive naturals, for example, 678006 + ... + 678636.

It is an arithmetic number, because the mean of its divisors is an integer number (11767840).

Almost surely, 2^428020551 is an apocalyptic number.

428020551 is a deficient number, since it is larger than the sum of its proper divisors (325121209).

428020551 is a wasteful number, since it uses less digits than its factorization.

428020551 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 781 (or 775 counting only the distinct ones).

The product of its (nonzero) digits is 3200, while the sum is 27.

The square root of 428020551 is about 20688.6575446548. The cubic root of 428020551 is about 753.6242660499.

The spelling of 428020551 in words is "four hundred twenty-eight million, twenty thousand, five hundred fifty-one".