521274989 has 4 divisors (see below), whose sum is σ = 525888156. Its totient is φ = 516661824.

The previous prime is 521274983. The next prime is 521274991. The reversal of 521274989 is 989472125.

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

It can be written as a sum of positive squares in 2 ways, for example, as 99301225 + 421973764 = 9965^2 + 20542^2 .

It is a cyclic number.

It is not a de Polignac number, because 521274989 - 2⁴ = 521274973 is a prime.

It is a super-2 number, since 2×521274989² = 543455228313900242, which contains 22 as substring.

It is an alternating number because its digits alternate between odd and even.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (521274983) 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, 2306414 + ... + 2306639.

It is an arithmetic number, because the mean of its divisors is an integer number (131472039).

Almost surely, 2^521274989 is an apocalyptic number.

It is an amenable number.

521274989 is a deficient number, since it is larger than the sum of its proper divisors (4613167).

521274989 is a wasteful number, since it uses less digits than its factorization.

521274989 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4613166.

The product of its digits is 362880, while the sum is 47.

The square root of 521274989 is about 22831.4473698012. The cubic root of 521274989 is about 804.8018436431.

The spelling of 521274989 in words is "five hundred twenty-one million, two hundred seventy-four thousand, nine hundred eighty-nine".