16781140 has 24 divisors (see below), whose sum is σ = 36456840. Its totient is φ = 6480768.

The previous prime is 16781129. The next prime is 16781143. The reversal of 16781140 is 4118761.

It can be written as a sum of positive squares in 4 ways, for example, as 1943236 + 14837904 = 1394^2 + 3852^2 .

It is a junction number, because it is equal to n+sod(n) for n = 16781099 and 16781108.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (16781143) 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, 13887 + ... + 15046.

It is an arithmetic number, because the mean of its divisors is an integer number (1519035).

Almost surely, 2^16781140 is an apocalyptic number.

16781140 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

16781140 is an abundant number, since it is smaller than the sum of its proper divisors (19675700).

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

16781140 is a wasteful number, since it uses less digits than its factorization.

16781140 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 28971 (or 28969 counting only the distinct ones).

The product of its (nonzero) digits is 1344, while the sum is 28.

The square root of 16781140 is about 4096.4789759011. The cubic root of 16781140 is about 256.0199569403.

The spelling of 16781140 in words is "sixteen million, seven hundred eighty-one thousand, one hundred forty".