521978361 has 8 divisors (see below), whose sum is σ = 699615744. Its totient is φ = 346163280.

The previous prime is 521978321. The next prime is 521978377. The reversal of 521978361 is 163879125.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 521978361 - 2²¹ = 519881209 is a prime.

It is a super-2 number, since 2×521978361² = 544922818704492642, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (521978311) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 454906 + ... + 456051.

It is an arithmetic number, because the mean of its divisors is an integer number (87451968).

Almost surely, 2^521978361 is an apocalyptic number.

It is an amenable number.

521978361 is a deficient number, since it is larger than the sum of its proper divisors (177637383).

521978361 is a wasteful number, since it uses less digits than its factorization.

521978361 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 911151.

The product of its digits is 90720, while the sum is 42.

The square root of 521978361 is about 22846.8457560338. The cubic root of 521978361 is about 805.1636620548.

The spelling of 521978361 in words is "five hundred twenty-one million, nine hundred seventy-eight thousand, three hundred sixty-one".