13905440 has 48 divisors (see below), whose sum is σ = 33081048. Its totient is φ = 5523456.

The previous prime is 13905433. The next prime is 13905461. The reversal of 13905440 is 4450931.

It is a Cunningham number, because it is equal to 3729²-1.

It can be written as a sum of positive squares in 4 ways, for example, as 9461776 + 4443664 = 3076^2 + 2108^2 .

It is a super-2 number, since 2×13905440² = 386722523187200, which contains 22 as substring.

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, 37094 + ... + 37466.

Almost surely, 2^13905440 is an apocalyptic number.

13905440 is a gapful number since it is divisible by the number (10) 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 13905440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (16540524).

13905440 is an abundant number, since it is smaller than the sum of its proper divisors (19175608).

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

13905440 is a wasteful number, since it uses less digits than its factorization.

13905440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 621 (or 613 counting only the distinct ones).

The product of its (nonzero) digits is 2160, while the sum is 26.

The square root of 13905440 is about 3728.9998659158. Note that the first 3 decimals coincide. The cubic root of 13905440 is about 240.4703738127.

The spelling of 13905440 in words is "thirteen million, nine hundred five thousand, four hundred forty".