20409860 has 24 divisors (see below), whose sum is σ = 45382680. Its totient is φ = 7683584.

The previous prime is 20409859. The next prime is 20409913. The reversal of 20409860 is 6890402.

It can be written as a sum of positive squares in 4 ways, for example, as 11600836 + 8809024 = 3406^2 + 2968^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 29675 + ... + 30354.

It is an arithmetic number, because the mean of its divisors is an integer number (1890945).

Almost surely, 2^20409860 is an apocalyptic number.

20409860 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20409860 is an abundant number, since it is smaller than the sum of its proper divisors (24972820).

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

20409860 is a wasteful number, since it uses less digits than its factorization.

20409860 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 60055 (or 60053 counting only the distinct ones).

The product of its (nonzero) digits is 3456, while the sum is 29.

The square root of 20409860 is about 4517.7273047407. The cubic root of 20409860 is about 273.2834564290.

The spelling of 20409860 in words is "twenty million, four hundred nine thousand, eight hundred sixty".