1221016045 has 8 divisors (see below), whose sum is σ = 1473315480. Its totient is φ = 971415360.

The previous prime is 1221016037. The next prime is 1221016051. The reversal of 1221016045 is 5406101221.

It can be written as a sum of positive squares in 4 ways, for example, as 4541161 + 1216474884 = 2131^2 + 34878^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 1221016045 - 2³ = 1221016037 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 673690 + ... + 675499.

It is an arithmetic number, because the mean of its divisors is an integer number (184164435).

Almost surely, 2^1221016045 is an apocalyptic number.

It is an amenable number.

1221016045 is a deficient number, since it is larger than the sum of its proper divisors (252299435).

1221016045 is a wasteful number, since it uses less digits than its factorization.

1221016045 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1349375.

The product of its (nonzero) digits is 480, while the sum is 22.

The square root of 1221016045 is about 34943.0400079901. The cubic root of 1221016045 is about 1068.8262801591.

Adding to 1221016045 its reverse (5406101221), we get a palindrome (6627117266).

The spelling of 1221016045 in words is "one billion, two hundred twenty-one million, sixteen thousand, forty-five".