20993101155 has 64 divisors (see below), whose sum is σ = 40485755520. Its totient is φ = 10259509248.

The previous prime is 20993101153. The next prime is 20993101183. The reversal of 20993101155 is 55110139902.

It is not a de Polignac number, because 20993101155 - 2¹ = 20993101153 is a prime.

It is a super-2 number, since 2×20993101155² (a number of 21 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (20993101153) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 196779 + ... + 284091.

It is an arithmetic number, because the mean of its divisors is an integer number (632589930).

Almost surely, 2^20993101155 is an apocalyptic number.

20993101155 is a deficient number, since it is larger than the sum of its proper divisors (19492654365).

20993101155 is a wasteful number, since it uses less digits than its factorization.

20993101155 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 87477 (or 87471 counting only the distinct ones).

The product of its (nonzero) digits is 12150, while the sum is 36.

The spelling of 20993101155 in words is "twenty billion, nine hundred ninety-three million, one hundred one thousand, one hundred fifty-five".