21510082445 has 4 divisors (see below), whose sum is σ = 25812098940. Its totient is φ = 17208065952.

The previous prime is 21510082441. The next prime is 21510082453. The reversal of 21510082445 is 54428001512.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 10766552644 + 10743529801 = 103762^2 + 103651^2 .

It is a cyclic number.

It is not a de Polignac number, because 21510082445 - 2² = 21510082441 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21510082441) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2151008240 + ... + 2151008249.

It is an arithmetic number, because the mean of its divisors is an integer number (6453024735).

Almost surely, 2^21510082445 is an apocalyptic number.

It is an amenable number.

21510082445 is a deficient number, since it is larger than the sum of its proper divisors (4302016495).

21510082445 is an equidigital number, since it uses as much as digits as its factorization.

21510082445 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4302016494.

The product of its (nonzero) digits is 12800, while the sum is 32.

Adding to 21510082445 its reverse (54428001512), we get a palindrome (75938083957).

The spelling of 21510082445 in words is "twenty-one billion, five hundred ten million, eighty-two thousand, four hundred forty-five".