21404155320305 has 16 divisors (see below), whose sum is σ = 25760675278800. Its totient is φ = 17072922639360.

The previous prime is 21404155320293. The next prime is 21404155320313. The reversal of 21404155320305 is 50302355140412.

It can be written as a sum of positive squares in 8 ways, for example, as 2423181015649 + 18980974304656 = 1556657^2 + 4356716^2 .

It is a de Polignac number, because none of the positive numbers 2^k-21404155320305 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 630860 + ... + 6573149.

It is an arithmetic number, because the mean of its divisors is an integer number (1610042204925).

Almost surely, 2^{21404155320305} is an apocalyptic number.

It is an amenable number.

21404155320305 is a deficient number, since it is larger than the sum of its proper divisors (4356519958495).

21404155320305 is a wasteful number, since it uses less digits than its factorization.

21404155320305 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7205764.

The product of its (nonzero) digits is 72000, while the sum is 35.

The spelling of 21404155320305 in words is "twenty-one trillion, four hundred four billion, one hundred fifty-five million, three hundred twenty thousand, three hundred five".