21779648906400 has 4320 divisors, whose sum is σ = 106013898676224. Its totient is φ = 4267904256000.

The previous prime is 21779648906399. The next prime is 21779648906401. The reversal of 21779648906400 is 460984697712.

21779648906400 is a `hidden beast` number, since 2 + 1 + 7 + 7 + 96 + 489 + 0 + 64 + 0 + 0 = 666.

It is an interprime number because it is at equal distance from previous prime (21779648906399) and next prime (21779648906401).

It is a tau number, because it is divible by the number of its divisors (4320).

It is a Harshad number since it is a multiple of its sum of digits (63).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21779648906401) by changing a digit.

It is a polite number, since it can be written in 719 ways as a sum of consecutive naturals, for example, 306755618365 + ... + 306755618435.

Almost surely, 2^{21779648906400} is an apocalyptic number.

21779648906400 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 21779648906400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (53006949338112).

21779648906400 is an abundant number, since it is smaller than the sum of its proper divisors (84234249769824).

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

21779648906400 is an equidigital number, since it uses as much as digits as its factorization.

21779648906400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 170 (or 122 counting only the distinct ones).

The product of its (nonzero) digits is 36578304, while the sum is 63.

The spelling of 21779648906400 in words is "twenty-one trillion, seven hundred seventy-nine billion, six hundred forty-eight million, nine hundred six thousand, four hundred".