20999487744 has 81 divisors (see below), whose sum is σ = 60566761983. Its totient is φ = 6997510656.

The previous prime is 20999487737. The next prime is 20999487767. The reversal of 20999487744 is 44778499902.

The square root of 20999487744 is 144912.

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

20999487744 is a `hidden beast` number, since 20 + 9 + 99 + 487 + 7 + 44 = 666.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 6954267 + ... + 6957285.

Almost surely, 2^20999487744 is an apocalyptic number.

20999487744 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

20999487744 is the 144912-nd square number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20999487744

20999487744 is an abundant number, since it is smaller than the sum of its proper divisors (39567274239).

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

20999487744 is an frugal number, since it uses more digits than its factorization.

20999487744 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6060 (or 3024 counting only the distinct ones).

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

The spelling of 20999487744 in words is "twenty billion, nine hundred ninety-nine million, four hundred eighty-seven thousand, seven hundred forty-four".