21166250769900 has 720 divisors, whose sum is σ = 75275029589760. Its totient is φ = 5121559756800.

The previous prime is 21166250769877. The next prime is 21166250769907. The reversal of 21166250769900 is 996705266112.

21166250769900 is a `hidden beast` number, since 2 + 1 + 1 + 6 + 625 + 0 + 7 + 6 + 9 + 9 + 0 + 0 = 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 (21166250769907) by changing a digit.

It is a polite number, since it can be written in 239 ways as a sum of consecutive naturals, for example, 1148271084 + ... + 1148289516.

It is an arithmetic number, because the mean of its divisors is an integer number (104548652208).

Almost surely, 2^{21166250769900} is an apocalyptic number.

21166250769900 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 21166250769900, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (37637514794880).

21166250769900 is an abundant number, since it is smaller than the sum of its proper divisors (54108778819860).

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

21166250769900 is a wasteful number, since it uses less digits than its factorization.

21166250769900 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18776 (or 18760 counting only the distinct ones).

The product of its (nonzero) digits is 2449440, while the sum is 54.

The spelling of 21166250769900 in words is "twenty-one trillion, one hundred sixty-six billion, two hundred fifty million, seven hundred sixty-nine thousand, nine hundred".