21532411345 has 4 divisors (see below), whose sum is σ = 25838893620. Its totient is φ = 17225929072.

The previous prime is 21532411343. The next prime is 21532411357. The reversal of 21532411345 is 54311423512.

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 12649725841 + 8882685504 = 112471^2 + 94248^2 .

It is a cyclic number.

It is not a de Polignac number, because 21532411345 - 2¹ = 21532411343 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21532411343) 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, 2153241130 + ... + 2153241139.

It is an arithmetic number, because the mean of its divisors is an integer number (6459723405).

Almost surely, 2^21532411345 is an apocalyptic number.

It is an amenable number.

21532411345 is a deficient number, since it is larger than the sum of its proper divisors (4306482275).

21532411345 is an equidigital number, since it uses as much as digits as its factorization.

21532411345 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4306482274.

The product of its digits is 14400, while the sum is 31.

Adding to 21532411345 its reverse (54311423512), we get a palindrome (75843834857).

The spelling of 21532411345 in words is "twenty-one billion, five hundred thirty-two million, four hundred eleven thousand, three hundred forty-five".