1220221545 has 16 divisors (see below), whose sum is σ = 2019677760. Its totient is φ = 628343744.

The previous prime is 1220221523. The next prime is 1220221559. The reversal of 1220221545 is 5451220221.

It is a cyclic number.

It is not a de Polignac number, because 1220221545 - 2⁶ = 1220221481 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1402119 + ... + 1402988.

It is an arithmetic number, because the mean of its divisors is an integer number (126229860).

Almost surely, 2^1220221545 is an apocalyptic number.

1220221545 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

1220221545 is a deficient number, since it is larger than the sum of its proper divisors (799456215).

1220221545 is a wasteful number, since it uses less digits than its factorization.

1220221545 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2805144.

The product of its (nonzero) digits is 1600, while the sum is 24.

The square root of 1220221545 is about 34931.6696566311. The cubic root of 1220221545 is about 1068.5944058568.

Adding to 1220221545 its reverse (5451220221), we get a palindrome (6671441766).

The spelling of 1220221545 in words is "one billion, two hundred twenty million, two hundred twenty-one thousand, five hundred forty-five".