21051654612120 has 320 divisors, whose sum is σ = 78056708637600. Its totient is φ = 5046088734720.

The previous prime is 21051654612077. The next prime is 21051654612143. The reversal of 21051654612120 is 2121645615012.

21051654612120 is a `hidden beast` number, since 2 + 1 + 0 + 5 + 16 + 5 + 4 + 612 + 1 + 20 = 666.

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

It is a congruent number.

It is an unprimeable number.

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, 146439 + ... + 6490358.

Almost surely, 2^{21051654612120} is an apocalyptic number.

21051654612120 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 21051654612120, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (39028354318800).

21051654612120 is an abundant number, since it is smaller than the sum of its proper divisors (57005054025480).

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

21051654612120 is a wasteful number, since it uses less digits than its factorization.

21051654612120 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6636920 (or 6636907 counting only the distinct ones).

The product of its (nonzero) digits is 28800, while the sum is 36.

The spelling of 21051654612120 in words is "twenty-one trillion, fifty-one billion, six hundred fifty-four million, six hundred twelve thousand, one hundred twenty".