21253365120445 has 32 divisors (see below), whose sum is σ = 26245305266400. Its totient is φ = 16515188112384.

The previous prime is 21253365120359. The next prime is 21253365120469. The reversal of 21253365120445 is 54402156335212.

It can be written as a sum of positive squares in 16 ways, for example, as 1821587514244 + 19431777606201 = 1349662^2 + 4408149^2 .

It is a cyclic number.

It is not a de Polignac number, because 21253365120445 - 2¹³ = 21253365112253 is a prime.

It is a super-3 number, since 3×21253365120445³ (a number of 41 digits) contains 333 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 34734211 + ... + 35340799.

It is an arithmetic number, because the mean of its divisors is an integer number (820165789575).

Almost surely, 2^{21253365120445} is an apocalyptic number.

It is an amenable number.

21253365120445 is a deficient number, since it is larger than the sum of its proper divisors (4991940145955).

21253365120445 is a wasteful number, since it uses less digits than its factorization.

21253365120445 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 607969.

The product of its (nonzero) digits is 864000, while the sum is 43.

The spelling of 21253365120445 in words is "twenty-one trillion, two hundred fifty-three billion, three hundred sixty-five million, one hundred twenty thousand, four hundred forty-five".