20520533155331 has 4 divisors (see below), whose sum is σ = 22386036169464. Its totient is φ = 18655030141200.

The previous prime is 20520533155301. The next prime is 20520533155457. The reversal of 20520533155331 is 13355133502502.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20520533155331 is a prime.

It is a super-2 number, since 2×20520533155331² (a number of 27 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (20520533155301) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 932751507050 + ... + 932751507071.

It is an arithmetic number, because the mean of its divisors is an integer number (5596509042366).

Almost surely, 2^{20520533155331} is an apocalyptic number.

20520533155331 is a deficient number, since it is larger than the sum of its proper divisors (1865503014133).

20520533155331 is a wasteful number, since it uses less digits than its factorization.

20520533155331 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1865503014132.

The product of its (nonzero) digits is 202500, while the sum is 38.

Adding to 20520533155331 its reverse (13355133502502), we get a palindrome (33875666657833).

The spelling of 20520533155331 in words is "twenty trillion, five hundred twenty billion, five hundred thirty-three million, one hundred fifty-five thousand, three hundred thirty-one".