21311758107880 has 32 divisors (see below), whose sum is σ = 47971132390440. Its totient is φ = 8521205172480.

The previous prime is 21311758107817. The next prime is 21311758107953. The reversal of 21311758107880 is 8870185711312.

It can be written as a sum of positive squares in 4 ways, for example, as 16646840642916 + 4664917464964 = 4080054^2 + 2159842^2 .

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 109216011 + ... + 109410970.

Almost surely, 2^{21311758107880} is an apocalyptic number.

21311758107880 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21311758107880 is an abundant number, since it is smaller than the sum of its proper divisors (26659374282560).

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

21311758107880 is a wasteful number, since it uses less digits than its factorization.

21311758107880 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 218629429 (or 218629425 counting only the distinct ones).

The product of its (nonzero) digits is 752640, while the sum is 52.

The spelling of 21311758107880 in words is "twenty-one trillion, three hundred eleven billion, seven hundred fifty-eight million, one hundred seven thousand, eight hundred eighty".