1220021001 has 8 divisors (see below), whose sum is σ = 1807438560. Its totient is φ = 813347316.

The previous prime is 1220020987. The next prime is 1220021009. The reversal of 1220021001 is 1001200221.

It is not a de Polignac number, because 1220021001 - 2²³ = 1211632393 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (9).

It is not an unprimeable number, because it can be changed into a prime (1220021009) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 22592955 + ... + 22593008.

It is an arithmetic number, because the mean of its divisors is an integer number (225929820).

Almost surely, 2^1220021001 is an apocalyptic number.

It is an amenable number.

1220021001 is a deficient number, since it is larger than the sum of its proper divisors (587417559).

1220021001 is an equidigital number, since it uses as much as digits as its factorization.

1220021001 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 45185972 (or 45185966 counting only the distinct ones).

The product of its (nonzero) digits is 8, while the sum is 9.

The square root of 1220021001 is about 34928.7990202927. The cubic root of 1220021001 is about 1068.5358613139.

Adding to 1220021001 its reverse (1001200221), we get a palindrome (2221221222).

The spelling of 1220021001 in words is "one billion, two hundred twenty million, twenty-one thousand, one".