1220326640 has 160 divisors (see below), whose sum is σ = 3377033856. Its totient is φ = 405504000.

The previous prime is 1220326633. The next prime is 1220326649. The reversal of 1220326640 is 466230221.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1220326649) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 405140 + ... + 408140.

Almost surely, 2^1220326640 is an apocalyptic number.

1220326640 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1220326640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1688516928).

1220326640 is an abundant number, since it is smaller than the sum of its proper divisors (2156707216).

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

1220326640 is a wasteful number, since it uses less digits than its factorization.

1220326640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3067 (or 3061 counting only the distinct ones).

The product of its (nonzero) digits is 3456, while the sum is 26.

The square root of 1220326640 is about 34933.1739182113. The cubic root of 1220326640 is about 1068.6250835387.

Adding to 1220326640 its reverse (466230221), we get a palindrome (1686556861).

The spelling of 1220326640 in words is "one billion, two hundred twenty million, three hundred twenty-six thousand, six hundred forty".