21801558301988 has 6 divisors (see below), whose sum is σ = 38152727028486. Its totient is φ = 10900779150992.

The previous prime is 21801558301987. The next prime is 21801558302011. The reversal of 21801558301988 is 88910385510812.

It can be written as a sum of positive squares in only one way, i.e., 19034652088384 + 2766906213604 = 4362872^2 + 1663402^2 .

It is a super-5 number, since 5×21801558301988⁵ (a number of 68 digits) contains 55555 as substring.

It is not an unprimeable number, because it can be changed into a prime (21801558301987) by changing a digit.

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 as a sum of consecutive naturals, namely, 2725194787745 + ... + 2725194787752.

It is an arithmetic number, because the mean of its divisors is an integer number (6358787838081).

Almost surely, 2^{21801558301988} is an apocalyptic number.

It is an amenable number.

21801558301988 is a deficient number, since it is larger than the sum of its proper divisors (16351168726498).

21801558301988 is a wasteful number, since it uses less digits than its factorization.

21801558301988 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5450389575501 (or 5450389575499 counting only the distinct ones).

The product of its (nonzero) digits is 5529600, while the sum is 59.

The spelling of 21801558301988 in words is "twenty-one trillion, eight hundred one billion, five hundred fifty-eight million, three hundred one thousand, nine hundred eighty-eight".