21154514004 has 72 divisors (see below), whose sum is σ = 57801711240. Its totient is φ = 6484845312.

The previous prime is 21154513997. The next prime is 21154514011. The reversal of 21154514004 is 40041545112.

21154514004 is a `hidden beast` number, since 211 + 5 + 45 + 1 + 400 + 4 = 666.

It is an interprime number because it is at equal distance from previous prime (21154513997) and next prime (21154514011).

It can be written as a sum of positive squares in 4 ways, for example, as 193265604 + 20961248400 = 13902^2 + 144780^2 .

It is a super-2 number, since 2×21154514004² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 41874 + ... + 209910.

It is an arithmetic number, because the mean of its divisors is an integer number (802801545).

Almost surely, 2^21154514004 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 21154514004, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28900855620).

21154514004 is an abundant number, since it is smaller than the sum of its proper divisors (36647197236).

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

21154514004 is a wasteful number, since it uses less digits than its factorization.

21154514004 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 168329 (or 168324 counting only the distinct ones).

The product of its (nonzero) digits is 3200, while the sum is 27.

The spelling of 21154514004 in words is "twenty-one billion, one hundred fifty-four million, five hundred fourteen thousand, four".