20261440 has 28 divisors (see below), whose sum is σ = 48248316. Its totient is φ = 8104448.

The previous prime is 20261431. The next prime is 20261497. The reversal of 20261440 is 4416202.

It can be written as a sum of positive squares in 2 ways, for example, as 3810304 + 16451136 = 1952^2 + 4056^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 31339 + ... + 31978.

Almost surely, 2^20261440 is an apocalyptic number.

20261440 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20261440 is an abundant number, since it is smaller than the sum of its proper divisors (27986876).

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

20261440 is an equidigital number, since it uses as much as digits as its factorization.

20261440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 63334 (or 63324 counting only the distinct ones).

The product of its (nonzero) digits is 384, while the sum is 19.

The square root of 20261440 is about 4501.2709316370. The cubic root of 20261440 is about 272.6194073105.

Adding to 20261440 its reverse (4416202), we get a palindrome (24677642).

The spelling of 20261440 in words is "twenty million, two hundred sixty-one thousand, four hundred forty".