427128561 has 12 divisors (see below), whose sum is σ = 643788288. Its totient is φ = 272371704.

The previous prime is 427128557. The next prime is 427128593. The reversal of 427128561 is 165821724.

427128561 is a `hidden beast` number, since 4 + 2 + 71 + 28 + 561 = 666.

It is not a de Polignac number, because 427128561 - 2² = 427128557 is a prime.

It is a super-3 number, since 3×427128561³ (a number of 27 digits) contains 333 as substring.

It is not an unprimeable number, because it can be changed into a prime (427128511) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1031505 + ... + 1031918.

It is an arithmetic number, because the mean of its divisors is an integer number (53649024).

Almost surely, 2^427128561 is an apocalyptic number.

It is an amenable number.

427128561 is a deficient number, since it is larger than the sum of its proper divisors (216659727).

427128561 is a wasteful number, since it uses less digits than its factorization.

427128561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2063452 (or 2063449 counting only the distinct ones).

The product of its digits is 26880, while the sum is 36.

The square root of 427128561 is about 20667.0888370859. The cubic root of 427128561 is about 753.1003871389.

The spelling of 427128561 in words is "four hundred twenty-seven million, one hundred twenty-eight thousand, five hundred sixty-one".