1220731904 has 66 divisors (see below), whose sum is σ = 2838800070. Its totient is φ = 523149312.

The previous prime is 1220731891. The next prime is 1220731927. The reversal of 1220731904 is 4091370221.

It can be written as a sum of positive squares in only one way, i.e., 1159266304 + 61465600 = 34048^2 + 7840^2 .

It is a hoax number, since the sum of its digits (29) coincides with the sum of the digits of its distinct prime factors.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 38012 + ... + 62340.

Almost surely, 2^1220731904 is an apocalyptic number.

1220731904 is a gapful number since it is divisible by the number (14) 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 1220731904, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1419400035).

1220731904 is an abundant number, since it is smaller than the sum of its proper divisors (1618068166).

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

1220731904 is an equidigital number, since it uses as much as digits as its factorization.

1220731904 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 24363 (or 24338 counting only the distinct ones).

The product of its (nonzero) digits is 3024, while the sum is 29.

The square root of 1220731904 is about 34938.9739975289. The cubic root of 1220731904 is about 1068.7433653522.

The spelling of 1220731904 in words is "one billion, two hundred twenty million, seven hundred thirty-one thousand, nine hundred four".