20345223521 has 8 divisors (see below), whose sum is σ = 23259862464. Its totient is φ = 17432629200.

The previous prime is 20345223439. The next prime is 20345223533. The reversal of 20345223521 is 12532254302.

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

It is a de Polignac number, because none of the positive numbers 2^k-20345223521 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20345223421) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 489770 + ... + 529683.

It is an arithmetic number, because the mean of its divisors is an integer number (2907482808).

Almost surely, 2^20345223521 is an apocalyptic number.

It is an amenable number.

20345223521 is a deficient number, since it is larger than the sum of its proper divisors (2914638943).

20345223521 is a wasteful number, since it uses less digits than its factorization.

20345223521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1022311.

The product of its (nonzero) digits is 14400, while the sum is 29.

Adding to 20345223521 its reverse (12532254302), we get a palindrome (32877477823).

The spelling of 20345223521 in words is "twenty billion, three hundred forty-five million, two hundred twenty-three thousand, five hundred twenty-one".