20847299521 has 8 divisors (see below), whose sum is σ = 21919765824. Its totient is φ = 19788671760.

The previous prime is 20847299503. The next prime is 20847299593. The reversal of 20847299521 is 12599274802.

It is a happy number.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20847299521 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20847299621) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3456546 + ... + 3462571.

It is an arithmetic number, because the mean of its divisors is an integer number (2739970728).

Almost surely, 2^20847299521 is an apocalyptic number.

It is an amenable number.

20847299521 is a deficient number, since it is larger than the sum of its proper divisors (1072466303).

20847299521 is a wasteful number, since it uses less digits than its factorization.

20847299521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6919271.

The product of its (nonzero) digits is 725760, while the sum is 49.

The spelling of 20847299521 in words is "twenty billion, eight hundred forty-seven million, two hundred ninety-nine thousand, five hundred twenty-one".