12640140 has 36 divisors (see below), whose sum is σ = 38342304. Its totient is φ = 3370656.

The previous prime is 12640123. The next prime is 12640141. The reversal of 12640140 is 4104621.

12640140 is a `hidden beast` number, since 12 + 640 + 14 + 0 = 666.

12640140 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a tau number, because it is divible by the number of its divisors (36).

It is a Harshad number since it is a multiple of its sum of digits (18).

It is not an unprimeable number, because it can be changed into a prime (12640141) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 34932 + ... + 35291.

It is an arithmetic number, because the mean of its divisors is an integer number (1065064).

Almost surely, 2^12640140 is an apocalyptic number.

12640140 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

12640140 is an abundant number, since it is smaller than the sum of its proper divisors (25702164).

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

12640140 is a wasteful number, since it uses less digits than its factorization.

12640140 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 70238 (or 70233 counting only the distinct ones).

The product of its (nonzero) digits is 192, while the sum is 18.

The square root of 12640140 is about 3555.2974559100. The cubic root of 12640140 is about 232.9435169195.

Adding to 12640140 its reverse (4104621), we get a palindrome (16744761).

The spelling of 12640140 in words is "twelve million, six hundred forty thousand, one hundred forty".