521381969 has 8 divisors (see below), whose sum is σ = 524190240. Its totient is φ = 518580000.

The previous prime is 521381929. The next prime is 521382031. The reversal of 521381969 is 969183125.

It is a happy number.

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 521381969 - 2¹² = 521377873 is a prime.

It is a super-2 number, since 2×521381969² = 543678315196633922, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (521381929) 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, 323237 + ... + 324845.

It is an arithmetic number, because the mean of its divisors is an integer number (65523780).

Almost surely, 2^521381969 is an apocalyptic number.

It is an amenable number.

521381969 is a deficient number, since it is larger than the sum of its proper divisors (2808271).

521381969 is a wasteful number, since it uses less digits than its factorization.

521381969 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3151.

The product of its digits is 116640, while the sum is 44.

The square root of 521381969 is about 22833.7900708577. The cubic root of 521381969 is about 804.8568957198.

The spelling of 521381969 in words is "five hundred twenty-one million, three hundred eighty-one thousand, nine hundred sixty-nine".