21454171776 has 96 divisors (see below), whose sum is σ = 62303369700. Its totient is φ = 7085740032.

The previous prime is 21454171769. The next prime is 21454171777. The reversal of 21454171776 is 67717145412.

21454171776 is a `hidden beast` number, since 21 + 4 + 541 + 7 + 17 + 76 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 18393869376 + 3060302400 = 135624^2 + 55320^2 .

It is a tau number, because it is divible by the number of its divisors (96).

It is a super-2 number, since 2×21454171776² (a number of 21 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21454171777) 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 11 ways as a sum of consecutive naturals, for example, 40140 + ... + 210996.

Almost surely, 2^21454171776 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21454171776, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (31151684850).

21454171776 is an abundant number, since it is smaller than the sum of its proper divisors (40849197924).

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

21454171776 is a wasteful number, since it uses less digits than its factorization.

21454171776 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 170986 (or 170971 counting only the distinct ones).

The product of its digits is 329280, while the sum is 45.

The spelling of 21454171776 in words is "twenty-one billion, four hundred fifty-four million, one hundred seventy-one thousand, seven hundred seventy-six".