408979840 has 64 divisors (see below), whose sum is σ = 990216000. Its totient is φ = 161501184.

The previous prime is 408979793. The next prime is 408979843. The reversal of 408979840 is 48979804.

It is a tau number, because it is divible by the number of its divisors (64).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (408979843) 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, 46516 + ... + 54604.

It is an arithmetic number, because the mean of its divisors is an integer number (15472125).

Almost surely, 2^408979840 is an apocalyptic number.

408979840 is a gapful number since it is divisible by the number (40) formed by its first and last digit.

408979840 is the 10112-nd decagonal number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 408979840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (495108000).

408979840 is an abundant number, since it is smaller than the sum of its proper divisors (581236160).

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

408979840 is an equidigital number, since it uses as much as digits as its factorization.

408979840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8187 (or 8175 counting only the distinct ones).

The product of its (nonzero) digits is 580608, while the sum is 49.

The square root of 408979840 is about 20223.2499860927. The cubic root of 408979840 is about 742.2792157594.

The spelling of 408979840 in words is "four hundred eight million, nine hundred seventy-nine thousand, eight hundred forty".