1221090023 has 4 divisors (see below), whose sum is σ = 1224942360. Its totient is φ = 1217237688.

The previous prime is 1221090007. The next prime is 1221090041. The reversal of 1221090023 is 3200901221.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 1221090023 - 2⁴ = 1221090007 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1221089977 and 1221090004.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1221090523) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1925693 + ... + 1926326.

It is an arithmetic number, because the mean of its divisors is an integer number (306235590).

Almost surely, 2^1221090023 is an apocalyptic number.

1221090023 is a deficient number, since it is larger than the sum of its proper divisors (3852337).

1221090023 is an equidigital number, since it uses as much as digits as its factorization.

1221090023 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3852336.

The product of its (nonzero) digits is 216, while the sum is 20.

The square root of 1221090023 is about 34944.0985432448. The cubic root of 1221090023 is about 1068.8478654702.

Adding to 1221090023 its reverse (3200901221), we get a palindrome (4421991244).

The spelling of 1221090023 in words is "one billion, two hundred twenty-one million, ninety thousand, twenty-three".