20689480 has 64 divisors (see below), whose sum is σ = 56016000. Its totient is φ = 6718464.

The previous prime is 20689477. The next prime is 20689481. The reversal of 20689480 is 8498602.

It is not an unprimeable number, because it can be changed into a prime (20689481) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3376 + ... + 7264.

It is an arithmetic number, because the mean of its divisors is an integer number (875250).

Almost surely, 2^20689480 is an apocalyptic number.

20689480 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 20689480, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28008000).

20689480 is an abundant number, since it is smaller than the sum of its proper divisors (35326520).

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

20689480 is a wasteful number, since it uses less digits than its factorization.

20689480 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3926 (or 3922 counting only the distinct ones).

The product of its (nonzero) digits is 27648, while the sum is 37.

The square root of 20689480 is about 4548.5690057424. The cubic root of 20689480 is about 274.5258164422.

The spelling of 20689480 in words is "twenty million, six hundred eighty-nine thousand, four hundred eighty".