20352656031721 has 16 divisors (see below), whose sum is σ = 22340358245520. Its totient is φ = 18425527511040.

The previous prime is 20352656031689. The next prime is 20352656031727. The reversal of 20352656031721 is 12713065625302.

It is a happy number.

It can be written as a sum of positive squares in 8 ways, for example, as 1553104167696 + 18799551864025 = 1246236^2 + 4335845^2 .

It is not a de Polignac number, because 20352656031721 - 2⁵ = 20352656031689 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20352656031727) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3863460 + ... + 7458661.

It is an arithmetic number, because the mean of its divisors is an integer number (1396272390345).

Almost surely, 2^{20352656031721} is an apocalyptic number.

It is an amenable number.

20352656031721 is a deficient number, since it is larger than the sum of its proper divisors (1987702213799).

20352656031721 is a wasteful number, since it uses less digits than its factorization.

20352656031721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11324796.

The product of its (nonzero) digits is 453600, while the sum is 43.

The spelling of 20352656031721 in words is "twenty trillion, three hundred fifty-two billion, six hundred fifty-six million, thirty-one thousand, seven hundred twenty-one".