20551433251455 has 24 divisors (see below), whose sum is σ = 36380409504192. Its totient is φ = 10727556646464.

The previous prime is 20551433251429. The next prime is 20551433251487. The reversal of 20551433251455 is 55415233415502.

20551433251455 is a `hidden beast` number, since 2 + 0 + 5 + 5 + 143 + 3 + 2 + 51 + 455 = 666.

It is not a de Polignac number, because 20551433251455 - 2⁸ = 20551433251199 is a prime.

It is a super-3 number, since 3×20551433251455³ (a number of 41 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a self number, because there is not a number n which added to its sum of digits gives 20551433251455.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 4858492744 + ... + 4858496973.

It is an arithmetic number, because the mean of its divisors is an integer number (1515850396008).

Almost surely, 2^{20551433251455} is an apocalyptic number.

20551433251455 is a deficient number, since it is larger than the sum of its proper divisors (15828976252737).

20551433251455 is a wasteful number, since it uses less digits than its factorization.

20551433251455 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9716989775 (or 9716989772 counting only the distinct ones).

The product of its (nonzero) digits is 1800000, while the sum is 45.

Adding to 20551433251455 its reverse (55415233415502), we get a palindrome (75966666666957).

The spelling of 20551433251455 in words is "twenty trillion, five hundred fifty-one billion, four hundred thirty-three million, two hundred fifty-one thousand, four hundred fifty-five".