21403678155552 has 2688 divisors, whose sum is σ = 85938147348480. Its totient is φ = 5121485107200.

The previous prime is 21403678155529. The next prime is 21403678155631. The reversal of 21403678155552 is 25555187630412.

21403678155552 is a `hidden beast` number, since 2 + 1 + 4 + 0 + 3 + 6 + 7 + 81 + 5 + 5 + 552 = 666.

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

It is an unprimeable number.

It is a polite number, since it can be written in 447 ways as a sum of consecutive naturals, for example, 293201070588 + ... + 293201070660.

It is an arithmetic number, because the mean of its divisors is an integer number (31971036960).

Almost surely, 2^{21403678155552} is an apocalyptic number.

21403678155552 is a gapful number since it is divisible by the number (22) 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 21403678155552, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (42969073674240).

21403678155552 is an abundant number, since it is smaller than the sum of its proper divisors (64534469192928).

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

21403678155552 is an equidigital number, since it uses as much as digits as its factorization.

21403678155552 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 231 (or 186 counting only the distinct ones).

The product of its (nonzero) digits is 10080000, while the sum is 54.

The spelling of 21403678155552 in words is "twenty-one trillion, four hundred three billion, six hundred seventy-eight million, one hundred fifty-five thousand, five hundred fifty-two".