12640155 has 16 divisors (see below), whose sum is σ = 22063104. Its totient is φ = 6128480.

The previous prime is 12640141. The next prime is 12640171. The reversal of 12640155 is 55104621.

It is not a de Polignac number, because 12640155 - 2⁵ = 12640123 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 38139 + ... + 38468.

It is an arithmetic number, because the mean of its divisors is an integer number (1378944).

Almost surely, 2^12640155 is an apocalyptic number.

12640155 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

12640155 is a deficient number, since it is larger than the sum of its proper divisors (9422949).

12640155 is a wasteful number, since it uses less digits than its factorization.

12640155 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 76626.

The product of its (nonzero) digits is 1200, while the sum is 24.

The square root of 12640155 is about 3555.2995654375. The cubic root of 12640155 is about 232.9436090639.

Adding to 12640155 its reverse (55104621), we get a palindrome (67744776).

The spelling of 12640155 in words is "twelve million, six hundred forty thousand, one hundred fifty-five".