520642021 has 8 divisors (see below), whose sum is σ = 523653984. Its totient is φ = 517638000.

The previous prime is 520641977. The next prime is 520642027. The reversal of 520642021 is 120246025.

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 520642021 - 2¹³ = 520633829 is a prime.

It is a super-2 number, since 2×520642021² = 542136228061928882, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 520641983 and 520642001.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (520642027) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 169915 + ... + 172951.

It is an arithmetic number, because the mean of its divisors is an integer number (65456748).

Almost surely, 2^520642021 is an apocalyptic number.

It is an amenable number.

520642021 is a deficient number, since it is larger than the sum of its proper divisors (3011963).

520642021 is a wasteful number, since it uses less digits than its factorization.

520642021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3971.

The product of its (nonzero) digits is 960, while the sum is 22.

The square root of 520642021 is about 22817.5814011915. The cubic root of 520642021 is about 804.4759630927.

Adding to 520642021 its reverse (120246025), we get a palindrome (640888046).

The spelling of 520642021 in words is "five hundred twenty million, six hundred forty-two thousand, twenty-one".