42823521 has 12 divisors (see below), whose sum is σ = 66614548. Its totient is φ = 26352864.

The previous prime is 42823513. The next prime is 42823553. The reversal of 42823521 is 12532824.

42823521 is a `hidden beast` number, since 428 + 235 + 2 + 1 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 22896225 + 19927296 = 4785^2 + 4464^2 .

It is not a de Polignac number, because 42823521 - 2³ = 42823513 is a prime.

It is not an unprimeable number, because it can be changed into a prime (42823421) 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, 182890 + ... + 183123.

Almost surely, 2^42823521 is an apocalyptic number.

It is an amenable number.

42823521 is a deficient number, since it is larger than the sum of its proper divisors (23791027).

42823521 is a wasteful number, since it uses less digits than its factorization.

42823521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 366032 (or 366029 counting only the distinct ones).

The product of its digits is 3840, while the sum is 27.

The square root of 42823521 is about 6543.9682914880. The cubic root of 42823521 is about 349.8598649879.

The spelling of 42823521 in words is "forty-two million, eight hundred twenty-three thousand, five hundred twenty-one".