1220890121 has 12 divisors (see below), whose sum is σ = 1355270532. Its totient is φ = 1098900000.

The previous prime is 1220890109. The next prime is 1220890123. The reversal of 1220890121 is 1210980221.

It can be written as a sum of positive squares in 2 ways, for example, as 1180884496 + 40005625 = 34364^2 + 6325^2 .

It is not a de Polignac number, because 1220890121 - 2¹⁸ = 1220627977 is a prime.

It is a super-4 number, since 4×1220890121⁴ (a number of 37 digits) contains 4444 as substring.

It is not an unprimeable number, because it can be changed into a prime (1220890123) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 37730 + ... + 62171.

It is an arithmetic number, because the mean of its divisors is an integer number (112939211).

Almost surely, 2^1220890121 is an apocalyptic number.

1220890121 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

1220890121 is a deficient number, since it is larger than the sum of its proper divisors (134380411).

1220890121 is a wasteful number, since it uses less digits than its factorization.

1220890121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 100024 (or 100013 counting only the distinct ones).

The product of its (nonzero) digits is 576, while the sum is 26.

The square root of 1220890121 is about 34941.2381148694. The cubic root of 1220890121 is about 1068.7895360316.

The spelling of 1220890121 in words is "one billion, two hundred twenty million, eight hundred ninety thousand, one hundred twenty-one".