428425615021 has 4 divisors (see below), whose sum is σ = 428481458172. Its totient is φ = 428369771872.

The previous prime is 428425614989. The next prime is 428425615027. The reversal of 428425615021 is 120516524824.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 340460580100 + 87965034921 = 583490^2 + 296589^2 .

It is a cyclic number.

It is not a de Polignac number, because 428425615021 - 2⁵ = 428425614989 is a prime.

It is a super-2 number, since 2×428425615021² (a number of 24 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (428425615027) 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, 27910066 + ... + 27925411.

It is an arithmetic number, because the mean of its divisors is an integer number (107120364543).

Almost surely, 2^428425615021 is an apocalyptic number.

It is an amenable number.

428425615021 is a deficient number, since it is larger than the sum of its proper divisors (55843151).

428425615021 is an equidigital number, since it uses as much as digits as its factorization.

428425615021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 55843150.

The product of its (nonzero) digits is 153600, while the sum is 40.

The spelling of 428425615021 in words is "four hundred twenty-eight billion, four hundred twenty-five million, six hundred fifteen thousand, twenty-one".