20645531554167 has 20 divisors (see below), whose sum is σ = 33213229301560. Its totient is φ = 12704942494224.

The previous prime is 20645531554121. The next prime is 20645531554187. The reversal of 20645531554167 is 76145513554602.

20645531554167 is a `hidden beast` number, since 2 + 0 + 6 + 4 + 5 + 5 + 31 + 5 + 541 + 67 = 666.

It is not a de Polignac number, because 20645531554167 - 2²⁰ = 20645530505591 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20645531554187) 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 19 ways as a sum of consecutive naturals, for example, 9803195317 + ... + 9803197422.

It is an arithmetic number, because the mean of its divisors is an integer number (1660661465078).

Almost surely, 2^{20645531554167} is an apocalyptic number.

20645531554167 is a gapful number since it is divisible by the number (27) formed by its first and last digit.

20645531554167 is a deficient number, since it is larger than the sum of its proper divisors (12567697747393).

20645531554167 is a wasteful number, since it uses less digits than its factorization.

20645531554167 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19606392764 (or 19606392755 counting only the distinct ones).

The product of its (nonzero) digits is 15120000, while the sum is 54.

The spelling of 20645531554167 in words is "twenty trillion, six hundred forty-five billion, five hundred thirty-one million, five hundred fifty-four thousand, one hundred sixty-seven".