20905689744 has 45 divisors (see below), whose sum is σ = 58511751753. Its totient is φ = 6967984896.

The previous prime is 20905689691. The next prime is 20905689809. The reversal of 20905689744 is 44798650902.

The square root of 20905689744 is 144588.

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

20905689744 is a `hidden beast` number, since 2 + 0 + 9 + 0 + 568 + 9 + 74 + 4 = 666.

It can be written as a sum of positive squares in only one way, i.e., 14402880144 + 6502809600 = 120012^2 + 80640^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 1729032 + ... + 1741080.

Almost surely, 2^20905689744 is an apocalyptic number.

20905689744 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

20905689744 is the 144588-th square number.

It is an amenable number.

20905689744 is an abundant number, since it is smaller than the sum of its proper divisors (37606062009).

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

20905689744 is an frugal number, since it uses more digits than its factorization.

20905689744 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24112 (or 12054 counting only the distinct ones).

The product of its (nonzero) digits is 4354560, while the sum is 54.

It can be divided in two parts, 20905 and 689744, that added together give a square (710649 = 843²).

The spelling of 20905689744 in words is "twenty billion, nine hundred five million, six hundred eighty-nine thousand, seven hundred forty-four".