20515404340 has 24 divisors (see below), whose sum is σ = 43411227552. Its totient is φ = 8143518240.

The previous prime is 20515404331. The next prime is 20515404379. The reversal of 20515404340 is 4340451502.

It is a junction number, because it is equal to n+sod(n) for n = 20515404299 and 20515404308.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3912534 + ... + 3917773.

It is an arithmetic number, because the mean of its divisors is an integer number (1808801148).

Almost surely, 2^20515404340 is an apocalyptic number.

20515404340 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20515404340 is an abundant number, since it is smaller than the sum of its proper divisors (22895823212).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

20515404340 is a wasteful number, since it uses less digits than its factorization.

20515404340 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7830447 (or 7830445 counting only the distinct ones).

The product of its (nonzero) digits is 9600, while the sum is 28.

Adding to 20515404340 its reverse (4340451502), we get a palindrome (24855855842).

The spelling of 20515404340 in words is "twenty billion, five hundred fifteen million, four hundred four thousand, three hundred forty".