1002220991 has 2 divisors, whose sum is σ = 1002220992. Its totient is φ = 1002220990.

The previous prime is 1002220981. The next prime is 1002221027. The reversal of 1002220991 is 1990222001.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1002220991 is a prime.

It is a super-3 number, since 3×1002220991³ (a number of 28 digits) contains 333 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 1002220991.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1002220931) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 501110495 + 501110496.

It is an arithmetic number, because the mean of its divisors is an integer number (501110496).

Almost surely, 2^1002220991 is an apocalyptic number.

1002220991 is a deficient number, since it is larger than the sum of its proper divisors (1).

1002220991 is an equidigital number, since it uses as much as digits as its factorization.

1002220991 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 648, while the sum is 26.

The square root of 1002220991 is about 31657.8740758125. The cubic root of 1002220991 is about 1000.7397829196.

Adding to 1002220991 its reverse (1990222001), we get a palindrome (2992442992).

It can be divided in two parts, 10022 and 20991, that added together give a palindrome (31013).

The spelling of 1002220991 in words is "one billion, two million, two hundred twenty thousand, nine hundred ninety-one".