21020191171092 has 72 divisors (see below), whose sum is σ = 53320567652352. Its totient is φ = 6982217640000.

The previous prime is 21020191171087. The next prime is 21020191171093. The reversal of 21020191171092 is 29017119102012.

21020191171092 is a `hidden beast` number, since 210 + 2 + 0 + 191 + 171 + 0 + 92 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21020191171093) 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 23 ways as a sum of consecutive naturals, for example, 11620333 + ... + 13306859.

It is an arithmetic number, because the mean of its divisors is an integer number (740563439616).

Almost surely, 2^{21020191171092} is an apocalyptic number.

It is an amenable number.

21020191171092 is an abundant number, since it is smaller than the sum of its proper divisors (32300376481260).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21020191171092 is a wasteful number, since it uses less digits than its factorization.

21020191171092 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1687749 (or 1687744 counting only the distinct ones).

The product of its (nonzero) digits is 4536, while the sum is 36.

The spelling of 21020191171092 in words is "twenty-one trillion, twenty billion, one hundred ninety-one million, one hundred seventy-one thousand, ninety-two".