20351643236645 has 16 divisors (see below), whose sum is σ = 27910979944320. Its totient is φ = 13955335038144.

The previous prime is 20351643236579. The next prime is 20351643236671. The reversal of 20351643236645 is 54663234615302.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 20351643236645 - 2⁸ = 20351643236389 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 20351643236593 and 20351643236602.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 5184674 + ... + 8220956.

It is an arithmetic number, because the mean of its divisors is an integer number (1744436246520).

Almost surely, 2^{20351643236645} is an apocalyptic number.

It is an amenable number.

20351643236645 is a deficient number, since it is larger than the sum of its proper divisors (7559336707675).

20351643236645 is a wasteful number, since it uses less digits than its factorization.

20351643236645 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3227804.

The product of its (nonzero) digits is 9331200, while the sum is 50.

The spelling of 20351643236645 in words is "twenty trillion, three hundred fifty-one billion, six hundred forty-three million, two hundred thirty-six thousand, six hundred forty-five".