12221378 has 32 divisors (see below), whose sum is σ = 20805120. Its totient is φ = 5345280.

The previous prime is 12221371. The next prime is 12221393. The reversal of 12221378 is 87312221.

It is a Harshad number since it is a multiple of its sum of digits (26).

It is not an unprimeable number, because it can be changed into a prime (12221371) 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, 47426 + ... + 47682.

It is an arithmetic number, because the mean of its divisors is an integer number (650160).

Almost surely, 2^12221378 is an apocalyptic number.

12221378 is a deficient number, since it is larger than the sum of its proper divisors (8583742).

12221378 is a wasteful number, since it uses less digits than its factorization.

12221378 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 362.

The product of its digits is 1344, while the sum is 26.

The square root of 12221378 is about 3495.9087516696. The cubic root of 12221378 is about 230.3421373029.

Adding to 12221378 its reverse (87312221), we get a palindrome (99533599).

The spelling of 12221378 in words is "twelve million, two hundred twenty-one thousand, three hundred seventy-eight".