1225640 has 32 divisors (see below), whose sum is σ = 2971080. Its totient is φ = 452352.

The previous prime is 1225621. The next prime is 1225643. The reversal of 1225640 is 465221.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 556516 + 669124 = 746^2 + 818^2 .

It is a Harshad number since it is a multiple of its sum of digits (20).

It is not an unprimeable number, because it can be changed into a prime (1225643) 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, 659 + ... + 1698.

2^1225640 is an apocalyptic number.

1225640 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1225640 is an abundant number, since it is smaller than the sum of its proper divisors (1745440).

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

1225640 is a wasteful number, since it uses less digits than its factorization.

1225640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2381 (or 2377 counting only the distinct ones).

The product of its (nonzero) digits is 480, while the sum is 20.

The square root of 1225640 is about 1107.0862658348. The cubic root of 1225640 is about 107.0173786080.

It can be divided in two parts, 12 and 25640, that added together give a palindrome (25652).

The spelling of 1225640 in words is "one million, two hundred twenty-five thousand, six hundred forty".