21154974120 has 320 divisors, whose sum is σ = 83886105600. Its totient is φ = 4679285760.

The previous prime is 21154974107. The next prime is 21154974121. The reversal of 21154974120 is 2147945112.

21154974120 is a `hidden beast` number, since 2 + 1 + 154 + 97 + 412 + 0 = 666.

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

It is not an unprimeable number, because it can be changed into a prime (21154974121) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 79 ways as a sum of consecutive naturals, for example, 688036 + ... + 718124.

It is an arithmetic number, because the mean of its divisors is an integer number (262144080).

Almost surely, 2^21154974120 is an apocalyptic number.

21154974120 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21154974120, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (41943052800).

21154974120 is an abundant number, since it is smaller than the sum of its proper divisors (62731131480).

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

21154974120 is a wasteful number, since it uses less digits than its factorization.

21154974120 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 30150 (or 30137 counting only the distinct ones).

The product of its (nonzero) digits is 20160, while the sum is 36.

The spelling of 21154974120 in words is "twenty-one billion, one hundred fifty-four million, nine hundred seventy-four thousand, one hundred twenty".