1221201045 has 12 divisors (see below), whose sum is σ = 2116748556. Its totient is φ = 651307200.

The previous prime is 1221201019. The next prime is 1221201083. The reversal of 1221201045 is 5401021221.

It can be written as a sum of positive squares in 2 ways, for example, as 310006449 + 911194596 = 17607^2 + 30186^2 .

It is not a de Polignac number, because 1221201045 - 2¹⁰ = 1221200021 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 13568856 + ... + 13568945.

It is an arithmetic number, because the mean of its divisors is an integer number (176395713).

Almost surely, 2^1221201045 is an apocalyptic number.

1221201045 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

1221201045 is a deficient number, since it is larger than the sum of its proper divisors (895547511).

1221201045 is a wasteful number, since it uses less digits than its factorization.

1221201045 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 27137812 (or 27137809 counting only the distinct ones).

The product of its (nonzero) digits is 160, while the sum is 18.

The square root of 1221201045 is about 34945.6870729422. The cubic root of 1221201045 is about 1068.8802578489.

Adding to 1221201045 its reverse (5401021221), we get a palindrome (6622222266).

The spelling of 1221201045 in words is "one billion, two hundred twenty-one million, two hundred one thousand, forty-five".