21531223045 has 8 divisors (see below), whose sum is σ = 25844104224. Its totient is φ = 17220554064.

The previous prime is 21531223037. The next prime is 21531223057. The reversal of 21531223045 is 54032213512.

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

It is a cyclic number.

It is not a de Polignac number, because 21531223045 - 2³ = 21531223037 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 531559 + ... + 570628.

It is an arithmetic number, because the mean of its divisors is an integer number (3230513028).

Almost surely, 2^21531223045 is an apocalyptic number.

It is an amenable number.

21531223045 is a deficient number, since it is larger than the sum of its proper divisors (4312881179).

21531223045 is a wasteful number, since it uses less digits than its factorization.

21531223045 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1106099.

The product of its (nonzero) digits is 7200, while the sum is 28.

Adding to 21531223045 its reverse (54032213512), we get a palindrome (75563436557).

The spelling of 21531223045 in words is "twenty-one billion, five hundred thirty-one million, two hundred twenty-three thousand, forty-five".