20581328974 has 4 divisors (see below), whose sum is σ = 30871993464. Its totient is φ = 10290664486.

The previous prime is 20581328969. The next prime is 20581329001. The reversal of 20581328974 is 47982318502.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 47982318502 = 2 ⋅23991159251.

It is a super-2 number, since 2×20581328974² (a number of 21 digits) contains 22 as substring.

It is a Smith number, since the sum of its digits (49) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a congruent number.

It is an unprimeable number.

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 as a sum of consecutive naturals, namely, 5145332242 + ... + 5145332245.

It is an arithmetic number, because the mean of its divisors is an integer number (7717998366).

Almost surely, 2^20581328974 is an apocalyptic number.

20581328974 is a deficient number, since it is larger than the sum of its proper divisors (10290664490).

20581328974 is a wasteful number, since it uses less digits than its factorization.

20581328974 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10290664489.

The product of its (nonzero) digits is 967680, while the sum is 49.

The spelling of 20581328974 in words is "twenty billion, five hundred eighty-one million, three hundred twenty-eight thousand, nine hundred seventy-four".