20679440 has 40 divisors (see below), whose sum is σ = 48752088. Its totient is φ = 8156160.

The previous prime is 20679433. The next prime is 20679469. The reversal of 20679440 is 4497602.

It can be written as a sum of positive squares in 4 ways, for example, as 1982464 + 18696976 = 1408^2 + 4324^2 .

It is a tau number, because it is divible by the number of its divisors (40).

It is a junction number, because it is equal to n+sod(n) for n = 20679397 and 20679406.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4070 + ... + 7610.

Almost surely, 2^20679440 is an apocalyptic number.

20679440 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 20679440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24376044).

20679440 is an abundant number, since it is smaller than the sum of its proper divisors (28072648).

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

20679440 is a wasteful number, since it uses less digits than its factorization.

20679440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3627 (or 3621 counting only the distinct ones).

The product of its (nonzero) digits is 12096, while the sum is 32.

The square root of 20679440 is about 4547.4652280144. The cubic root of 20679440 is about 274.4814028053.

The spelling of 20679440 in words is "twenty million, six hundred seventy-nine thousand, four hundred forty".