1220518906 has 4 divisors (see below), whose sum is σ = 1830778362. Its totient is φ = 610259452.

The previous prime is 1220518883. The next prime is 1220518907. The reversal of 1220518906 is 6098150221.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 6098150221 = 43 ⋅141817447.

It can be written as a sum of positive squares in only one way, i.e., 1219057225 + 1461681 = 34915^2 + 1209^2 .

It is not an unprimeable number, because it can be changed into a prime (1220518907) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 305129725 + ... + 305129728.

Almost surely, 2^1220518906 is an apocalyptic number.

1220518906 is a deficient number, since it is larger than the sum of its proper divisors (610259456).

1220518906 is an equidigital number, since it uses as much as digits as its factorization.

1220518906 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 610259455.

The product of its (nonzero) digits is 8640, while the sum is 34.

The square root of 1220518906 is about 34935.9257212400. The cubic root of 1220518906 is about 1068.6812022516.

The spelling of 1220518906 in words is "one billion, two hundred twenty million, five hundred eighteen thousand, nine hundred six".