21056136445 has 8 divisors (see below), whose sum is σ = 25275326040. Its totient is φ = 16839600960.

The previous prime is 21056136443. The next prime is 21056136449. The reversal of 21056136445 is 54463165012.

It can be written as a sum of positive squares in 4 ways, for example, as 3626327961 + 17429808484 = 60219^2 + 132022^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 21056136445 - 2¹ = 21056136443 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21056136443) 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 in 7 ways as a sum of consecutive naturals, for example, 646030 + ... + 677839.

It is an arithmetic number, because the mean of its divisors is an integer number (3159415755).

Almost surely, 2^21056136445 is an apocalyptic number.

It is an amenable number.

21056136445 is a deficient number, since it is larger than the sum of its proper divisors (4219189595).

21056136445 is a wasteful number, since it uses less digits than its factorization.

21056136445 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1327055.

The product of its (nonzero) digits is 86400, while the sum is 37.

The spelling of 21056136445 in words is "twenty-one billion, fifty-six million, one hundred thirty-six thousand, four hundred forty-five".