20849680 has 40 divisors (see below), whose sum is σ = 49104000. Its totient is φ = 8231808.

The previous prime is 20849677. The next prime is 20849681. The reversal of 20849680 is 8694802.

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

It is a super-2 number, since 2×20849680² = 869418312204800, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (20849681) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4671 + ... + 7969.

It is an arithmetic number, because the mean of its divisors is an integer number (1227600).

Almost surely, 2^20849680 is an apocalyptic number.

20849680 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 20849680, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24552000).

20849680 is an abundant number, since it is smaller than the sum of its proper divisors (28254320).

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

20849680 is a wasteful number, since it uses less digits than its factorization.

20849680 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3391 (or 3385 counting only the distinct ones).

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

The square root of 20849680 is about 4566.1449823675. The cubic root of 20849680 is about 275.2325525987.

The spelling of 20849680 in words is "twenty million, eight hundred forty-nine thousand, six hundred eighty".