23781440 has 28 divisors (see below), whose sum is σ = 56630316. Its totient is φ = 9512448.

The previous prime is 23781437. The next prime is 23781463. The reversal of 23781440 is 4418732.

It can be written as a sum of positive squares in 2 ways, for example, as 10705984 + 13075456 = 3272^2 + 3616^2 .

It is a hoax number, since the sum of its digits (29) coincides with the sum of the digits of its distinct prime factors.

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, 36839 + ... + 37478.

Almost surely, 2^23781440 is an apocalyptic number.

23781440 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

23781440 is an abundant number, since it is smaller than the sum of its proper divisors (32848876).

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

23781440 is an equidigital number, since it uses as much as digits as its factorization.

23781440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 74334 (or 74324 counting only the distinct ones).

The product of its (nonzero) digits is 5376, while the sum is 29.

The square root of 23781440 is about 4876.6217815205. The cubic root of 23781440 is about 287.5716368430.

The spelling of 23781440 in words is "twenty-three million, seven hundred eighty-one thousand, four hundred forty".