20343665156321 has 4 divisors (see below), whose sum is σ = 21908562476052. Its totient is φ = 18778767836592.

The previous prime is 20343665156257. The next prime is 20343665156323. The reversal of 20343665156321 is 12365156634302.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 5271450689296 + 15072214467025 = 2295964^2 + 3882295^2 .

It is a cyclic number.

It is not a de Polignac number, because 20343665156321 - 2⁶ = 20343665156257 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20343665156323) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 782448659846 + ... + 782448659871.

It is an arithmetic number, because the mean of its divisors is an integer number (5477140619013).

Almost surely, 2^{20343665156321} is an apocalyptic number.

It is an amenable number.

20343665156321 is a deficient number, since it is larger than the sum of its proper divisors (1564897319731).

20343665156321 is a wasteful number, since it uses less digits than its factorization.

20343665156321 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1564897319730.

The product of its (nonzero) digits is 2332800, while the sum is 47.

The spelling of 20343665156321 in words is "twenty trillion, three hundred forty-three billion, six hundred sixty-five million, one hundred fifty-six thousand, three hundred twenty-one".