39784690521 has 27 divisors (see below), whose sum is σ = 61061633503. Its totient is φ = 24956560320.

The previous prime is 39784690489. The next prime is 39784690529. The reversal of 39784690521 is 12509648793.

The square root of 39784690521 is 199461.

It is a perfect power (a square), and thus also a powerful number.

39784690521 is a `hidden beast` number, since 3 + 9 + 78 + 46 + 9 + 0 + 521 = 666.

It can be written as a sum of positive squares in only one way, i.e., 30974240025 + 8810450496 = 175995^2 + 93864^2 .

It is not a de Polignac number, because 39784690521 - 2⁵ = 39784690489 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (39784690529) 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 26 ways as a sum of consecutive naturals, for example, 10170556 + ... + 10174466.

It is a 2-persistent number, because it is pandigital, and so is 2⋅39784690521 = 79569381042, but 3⋅39784690521 = 119354071563 is not.

Almost surely, 2^39784690521 is an apocalyptic number.

39784690521 is the 199461-st square number.

39784690521 is the 99731-st centered octagonal number.

It is an amenable number.

39784690521 is a deficient number, since it is larger than the sum of its proper divisors (21276942982).

39784690521 is an frugal number, since it uses more digits than its factorization.

39784690521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7862 (or 3931 counting only the distinct ones).

The product of its (nonzero) digits is 3265920, while the sum is 54.

The spelling of 39784690521 in words is "thirty-nine billion, seven hundred eighty-four million, six hundred ninety thousand, five hundred twenty-one".