20689945600 has 297 divisors, whose sum is σ = 54884149671. Its totient is φ = 7732838400.

The previous prime is 20689945597. The next prime is 20689945643. The reversal of 20689945600 is 654998602.

The square root of 20689945600 is 143840.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in 4 ways, for example, as 284394496 + 20405551104 = 16864^2 + 142848^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 667417585 + ... + 667417615.

Almost surely, 2^20689945600 is an apocalyptic number.

20689945600 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

20689945600 is the 143840-th square number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20689945600

20689945600 is an abundant number, since it is smaller than the sum of its proper divisors (34194204071).

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

20689945600 is an equidigital number, since it uses as much as digits as its factorization.

20689945600 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 150 (or 67 counting only the distinct ones).

The product of its (nonzero) digits is 933120, while the sum is 49.

Multiplying 20689945600 by its sum of digits (49), we get a square (1013807334400 = 1006880²).

It can be divided in two parts, 20689 and 945600, that added together give a square (966289 = 983²).

The spelling of 20689945600 in words is "twenty billion, six hundred eighty-nine million, nine hundred forty-five thousand, six hundred".