1220432640 has 144 divisors (see below), whose sum is σ = 4454677248. Its totient is φ = 278949888.

The previous prime is 1220432599. The next prime is 1220432677. The reversal of 1220432640 is 462340221.

It is a Harshad number since it is a multiple of its sum of digits (24).

It is a self number, because there is not a number n which added to its sum of digits gives 1220432640.

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, 4179 + ... + 49581.

Almost surely, 2^1220432640 is an apocalyptic number.

1220432640 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 1220432640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2227338624).

1220432640 is an abundant number, since it is smaller than the sum of its proper divisors (3234244608).

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

1220432640 is an equidigital number, since it uses as much as digits as its factorization.

1220432640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 45434 (or 45420 counting only the distinct ones).

The product of its (nonzero) digits is 2304, while the sum is 24.

The square root of 1220432640 is about 34934.6910677624. The cubic root of 1220432640 is about 1068.6560236098.

Adding to 1220432640 its reverse (462340221), we get a palindrome (1682772861).

It can be divided in two parts, 12204 and 32640, that added together give a palindrome (44844).

The spelling of 1220432640 in words is "one billion, two hundred twenty million, four hundred thirty-two thousand, six hundred forty".