521021073 has 4 divisors (see below), whose sum is σ = 694694768. Its totient is φ = 347347380.

The previous prime is 521021057. The next prime is 521021101. The reversal of 521021073 is 370120125.

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 not a de Polignac number, because 521021073 - 2⁴ = 521021057 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (521021003) 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, 86836843 + ... + 86836848.

It is an arithmetic number, because the mean of its divisors is an integer number (173673692).

Almost surely, 2^521021073 is an apocalyptic number.

It is an amenable number.

521021073 is a deficient number, since it is larger than the sum of its proper divisors (173673695).

521021073 is a wasteful number, since it uses less digits than its factorization.

521021073 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 173673694.

The product of its (nonzero) digits is 420, while the sum is 21.

The square root of 521021073 is about 22825.8860288051. The cubic root of 521021073 is about 804.6711479076.

Adding to 521021073 its reverse (370120125), we get a palindrome (891141198).

The spelling of 521021073 in words is "five hundred twenty-one million, twenty-one thousand, seventy-three".