20991504707348 has 18 divisors (see below), whose sum is σ = 42732706011786. Its totient is φ = 8996359160208.

The previous prime is 20991504707347. The next prime is 20991504707363. The reversal of 20991504707348 is 84370740519902.

It can be written as a sum of positive squares in only one way, i.e., 10964389807504 + 10027114899844 = 3311252^2 + 3166562^2 .

It is a super-2 number, since 2×20991504707348² (a number of 27 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20991504707347) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 53549756711 + ... + 53549757102.

It is an arithmetic number, because the mean of its divisors is an integer number (2374039222877).

Almost surely, 2^{20991504707348} is an apocalyptic number.

20991504707348 is a gapful number since it is divisible by the number (28) formed by its first and last digit.

It is an amenable number.

20991504707348 is an abundant number, since it is smaller than the sum of its proper divisors (21741201304438).

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

20991504707348 is a wasteful number, since it uses less digits than its factorization.

20991504707348 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 107099513831 (or 107099513822 counting only the distinct ones).

The product of its (nonzero) digits is 15240960, while the sum is 59.

The spelling of 20991504707348 in words is "twenty trillion, nine hundred ninety-one billion, five hundred four million, seven hundred seven thousand, three hundred forty-eight".