12640215 has 16 divisors (see below), whose sum is σ = 23113728. Its totient is φ = 5778336.

The previous prime is 12640211. The next prime is 12640217. The reversal of 12640215 is 51204621.

It is not a de Polignac number, because 12640215 - 2² = 12640211 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is a junction number, because it is equal to n+sod(n) for n = 12640191 and 12640200.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12640211) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 60087 + ... + 60296.

It is an arithmetic number, because the mean of its divisors is an integer number (1444608).

Almost surely, 2^12640215 is an apocalyptic number.

12640215 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

12640215 is a deficient number, since it is larger than the sum of its proper divisors (10473513).

12640215 is a wasteful number, since it uses less digits than its factorization.

12640215 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 120398.

The product of its (nonzero) digits is 480, while the sum is 21.

The square root of 12640215 is about 3555.3080035350. The cubic root of 12640215 is about 232.9439776404.

Adding to 12640215 its reverse (51204621), we get a palindrome (63844836).

The spelling of 12640215 in words is "twelve million, six hundred forty thousand, two hundred fifteen".