21124651276872 has 256 divisors, whose sum is σ = 69789353760000. Its totient is φ = 5908992664320.

The previous prime is 21124651276843. The next prime is 21124651276879. The reversal of 21124651276872 is 27867215642112.

21124651276872 is a `hidden beast` number, since 2 + 1 + 1 + 2 + 46 + 512 + 7 + 6 + 87 + 2 = 666.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is not an unprimeable number, because it can be changed into a prime (21124651276879) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 1719747 + ... + 6723602.

It is an arithmetic number, because the mean of its divisors is an integer number (272614663125).

Almost surely, 2^{21124651276872} is an apocalyptic number.

21124651276872 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

It is an amenable number.

21124651276872 is an abundant number, since it is smaller than the sum of its proper divisors (48664702483128).

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

21124651276872 is a wasteful number, since it uses less digits than its factorization.

21124651276872 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8443400 (or 8443378 counting only the distinct ones).

The product of its digits is 4515840, while the sum is 54.

The spelling of 21124651276872 in words is "twenty-one trillion, one hundred twenty-four billion, six hundred fifty-one million, two hundred seventy-six thousand, eight hundred seventy-two".