1220120655 has 16 divisors (see below), whose sum is σ = 2102362080. Its totient is φ = 600674688.

The previous prime is 1220120653. The next prime is 1220120659. The reversal of 1220120655 is 5560210221.

It is a happy number.

It is not a de Polignac number, because 1220120655 - 2¹ = 1220120653 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1220120653) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3128320 + ... + 3128709.

It is an arithmetic number, because the mean of its divisors is an integer number (131397630).

Almost surely, 2^1220120655 is an apocalyptic number.

1220120655 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

1220120655 is a deficient number, since it is larger than the sum of its proper divisors (882241425).

1220120655 is a wasteful number, since it uses less digits than its factorization.

1220120655 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6257050.

The product of its (nonzero) digits is 1200, while the sum is 24.

The square root of 1220120655 is about 34930.2255217455. The cubic root of 1220120655 is about 1068.5649539753.

Adding to 1220120655 its reverse (5560210221), we get a palindrome (6780330876).

The spelling of 1220120655 in words is "one billion, two hundred twenty million, one hundred twenty thousand, six hundred fifty-five".