521972837 has 4 divisors (see below), whose sum is σ = 522018540. Its totient is φ = 521927136.

The previous prime is 521972819. The next prime is 521972839. The reversal of 521972837 is 738279125.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 125126596 + 396846241 = 11186^2 + 19921^2 .

It is a cyclic number.

It is not a de Polignac number, because 521972837 - 2¹⁴ = 521956453 is a prime.

It is a super-3 number, since 3×521972837³ (a number of 27 digits) contains 333 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (521972839) 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, 10763 + ... + 34055.

It is an arithmetic number, because the mean of its divisors is an integer number (130504635).

Almost surely, 2^521972837 is an apocalyptic number.

It is an amenable number.

521972837 is a deficient number, since it is larger than the sum of its proper divisors (45703).

521972837 is a wasteful number, since it uses less digits than its factorization.

521972837 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 45702.

The product of its digits is 211680, while the sum is 44.

The square root of 521972837 is about 22846.7248637524. The cubic root of 521972837 is about 805.1608217456.

The spelling of 521972837 in words is "five hundred twenty-one million, nine hundred seventy-two thousand, eight hundred thirty-seven".