20980640349 has 6 divisors (see below), whose sum is σ = 30305369406. Its totient is φ = 13987093560.

The previous prime is 20980640297. The next prime is 20980640363. The reversal of 20980640349 is 94304608902.

It can be written as a sum of positive squares in only one way, i.e., 19791425124 + 1189215225 = 140682^2 + 34485^2 .

It is not a de Polignac number, because 20980640349 - 2¹² = 20980636253 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20980640449) 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 5 ways as a sum of consecutive naturals, for example, 1165591122 + ... + 1165591139.

It is an arithmetic number, because the mean of its divisors is an integer number (5050894901).

Almost surely, 2^20980640349 is an apocalyptic number.

It is an amenable number.

20980640349 is a deficient number, since it is larger than the sum of its proper divisors (9324729057).

20980640349 is a wasteful number, since it uses less digits than its factorization.

20980640349 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2331182267 (or 2331182264 counting only the distinct ones).

The product of its (nonzero) digits is 373248, while the sum is 45.

The spelling of 20980640349 in words is "twenty billion, nine hundred eighty million, six hundred forty thousand, three hundred forty-nine".