21044132345 has 4 divisors (see below), whose sum is σ = 25252958820. Its totient is φ = 16835305872.

The previous prime is 21044132341. The next prime is 21044132377. The reversal of 21044132345 is 54323144012.

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 8313974761 + 12730157584 = 91181^2 + 112828^2 .

It is a cyclic number.

It is not a de Polignac number, because 21044132345 - 2² = 21044132341 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21044132341) 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, 2104413230 + ... + 2104413239.

It is an arithmetic number, because the mean of its divisors is an integer number (6313239705).

Almost surely, 2^21044132345 is an apocalyptic number.

It is an amenable number.

21044132345 is a deficient number, since it is larger than the sum of its proper divisors (4208826475).

21044132345 is an equidigital number, since it uses as much as digits as its factorization.

21044132345 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4208826474.

The product of its (nonzero) digits is 11520, while the sum is 29.

Adding to 21044132345 its reverse (54323144012), we get a palindrome (75367276357).

The spelling of 21044132345 in words is "twenty-one billion, forty-four million, one hundred thirty-two thousand, three hundred forty-five".