20834732581 has 8 divisors (see below), whose sum is σ = 22659558264. Its totient is φ = 19041643200.

The previous prime is 20834732561. The next prime is 20834732609. The reversal of 20834732581 is 18523743802.

20834732581 = 102065² + 102066².

It can be written as a sum of positive squares in 4 ways, for example, as 6373467556 + 14461265025 = 79834^2 + 120255^2 .

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 20834732581 - 2⁹ = 20834732069 is a prime.

It is a super-2 number, since 2×20834732581² (a number of 21 digits) contains 22 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 (20834732521) 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, 7932706 + ... + 7935331.

It is an arithmetic number, because the mean of its divisors is an integer number (2832444783).

Almost surely, 2^20834732581 is an apocalyptic number.

20834732581 is the 102066-th centered square number.

It is an amenable number.

20834732581 is a deficient number, since it is larger than the sum of its proper divisors (1824825683).

20834732581 is a wasteful number, since it uses less digits than its factorization.

20834732581 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15868151.

The product of its (nonzero) digits is 322560, while the sum is 43.

The spelling of 20834732581 in words is "twenty billion, eight hundred thirty-four million, seven hundred thirty-two thousand, five hundred eighty-one".