521206474 has 4 divisors (see below), whose sum is σ = 781809714. Its totient is φ = 260603236.

The previous prime is 521206459. The next prime is 521206481. The reversal of 521206474 is 474602125.

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

It can be written as a sum of positive squares in only one way, i.e., 452200225 + 69006249 = 21265^2 + 8307^2 .

It is a Smith number, since the sum of its digits (31) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 130301617 + ... + 130301620.

Almost surely, 2^521206474 is an apocalyptic number.

521206474 is a deficient number, since it is larger than the sum of its proper divisors (260603240).

521206474 is a wasteful number, since it uses less digits than its factorization.

521206474 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 260603239.

The product of its (nonzero) digits is 13440, while the sum is 31.

The square root of 521206474 is about 22829.9468680941. The cubic root of 521206474 is about 804.7665817593.

Adding to 521206474 its reverse (474602125), we get a palindrome (995808599).

The spelling of 521206474 in words is "five hundred twenty-one million, two hundred six thousand, four hundred seventy-four".