21153320545 has 8 divisors (see below), whose sum is σ = 29010268224. Its totient is φ = 14505134064.

The previous prime is 21153320537. The next prime is 21153320633. The reversal of 21153320545 is 54502335112.

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 21153320545 - 2³ = 21153320537 is a prime.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 302190259 + ... + 302190328.

It is an arithmetic number, because the mean of its divisors is an integer number (3626283528).

Almost surely, 2^21153320545 is an apocalyptic number.

It is an amenable number.

21153320545 is a deficient number, since it is larger than the sum of its proper divisors (7856947679).

21153320545 is an equidigital number, since it uses as much as digits as its factorization.

21153320545 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 604380599.

The product of its (nonzero) digits is 18000, while the sum is 31.

Adding to 21153320545 its reverse (54502335112), we get a palindrome (75655655657).

The spelling of 21153320545 in words is "twenty-one billion, one hundred fifty-three million, three hundred twenty thousand, five hundred forty-five".