428167821 has 8 divisors (see below), whose sum is σ = 574080480. Its totient is φ = 283850192.

The previous prime is 428167799. The next prime is 428167823. The reversal of 428167821 is 128761824.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 428167821 - 2⁶ = 428167757 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 428167821.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (428167823) 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 7 ways as a sum of consecutive naturals, for example, 398130 + ... + 399203.

It is an arithmetic number, because the mean of its divisors is an integer number (71760060).

Almost surely, 2^428167821 is an apocalyptic number.

It is an amenable number.

428167821 is a deficient number, since it is larger than the sum of its proper divisors (145912659).

428167821 is a wasteful number, since it uses less digits than its factorization.

428167821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 797515.

The product of its digits is 43008, while the sum is 39.

The square root of 428167821 is about 20692.2164351719. The cubic root of 428167821 is about 753.7106898745.

The spelling of 428167821 in words is "four hundred twenty-eight million, one hundred sixty-seven thousand, eight hundred twenty-one".