21954119163781 has 16 divisors (see below), whose sum is σ = 25195864896000. Its totient is φ = 18738737071488.

The previous prime is 21954119163673. The next prime is 21954119163827. The reversal of 21954119163781 is 18736191145912.

It is not a de Polignac number, because 21954119163781 - 2⁷ = 21954119163653 is a prime.

It is a super-2 number, since 2×21954119163781² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21954119163181) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (29) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 139531551 + ... + 139688803.

It is an arithmetic number, because the mean of its divisors is an integer number (1574741556000).

Almost surely, 2^{21954119163781} is an apocalyptic number.

It is an amenable number.

21954119163781 is a deficient number, since it is larger than the sum of its proper divisors (3241745732219).

21954119163781 is a wasteful number, since it uses less digits than its factorization.

21954119163781 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 240948.

The product of its digits is 3265920, while the sum is 58.

The spelling of 21954119163781 in words is "twenty-one trillion, nine hundred fifty-four billion, one hundred nineteen million, one hundred sixty-three thousand, seven hundred eighty-one".