20645251500355 has 16 divisors (see below), whose sum is σ = 24798363120000. Its totient is φ = 16500168115200.

The previous prime is 20645251500353. The next prime is 20645251500383. The reversal of 20645251500355 is 55300515254602.

It is not a de Polignac number, because 20645251500355 - 2¹ = 20645251500353 is a prime.

It is not an unprimeable number, because it can be changed into a prime (20645251500353) 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, 20794255 + ... + 21764455.

It is an arithmetic number, because the mean of its divisors is an integer number (1549897695000).

Almost surely, 2^{20645251500355} is an apocalyptic number.

20645251500355 is a deficient number, since it is larger than the sum of its proper divisors (4153111619645).

20645251500355 is a wasteful number, since it uses less digits than its factorization.

20645251500355 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 974334.

The product of its (nonzero) digits is 900000, while the sum is 43.

Adding to 20645251500355 its reverse (55300515254602), we get a palindrome (75945766754957).

The spelling of 20645251500355 in words is "twenty trillion, six hundred forty-five billion, two hundred fifty-one million, five hundred thousand, three hundred fifty-five".