428280621 has 4 divisors (see below), whose sum is σ = 571040832. Its totient is φ = 285520412.

The previous prime is 428280599. The next prime is 428280623. The reversal of 428280621 is 126082824.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 428280621 - 2¹⁷ = 428149549 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (428280623) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 71380101 + ... + 71380106.

It is an arithmetic number, because the mean of its divisors is an integer number (142760208).

Almost surely, 2^428280621 is an apocalyptic number.

It is an amenable number.

428280621 is a deficient number, since it is larger than the sum of its proper divisors (142760211).

428280621 is a wasteful number, since it uses less digits than its factorization.

428280621 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 142760210.

The product of its (nonzero) digits is 12288, while the sum is 33.

The square root of 428280621 is about 20694.9419182563. The cubic root of 428280621 is about 753.7768719467.

The spelling of 428280621 in words is "four hundred twenty-eight million, two hundred eighty thousand, six hundred twenty-one".