1221550073 has 2 divisors, whose sum is σ = 1221550074. Its totient is φ = 1221550072.

The previous prime is 1221550049. The next prime is 1221550117. The reversal of 1221550073 is 3700551221.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1203257344 + 18292729 = 34688^2 + 4277^2 .

It is a cyclic number.

It is not a de Polignac number, because 1221550073 - 2¹⁸ = 1221287929 is a prime.

It is not a weakly prime, because it can be changed into another prime (1221550013) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 610775036 + 610775037.

It is an arithmetic number, because the mean of its divisors is an integer number (610775037).

Almost surely, 2^1221550073 is an apocalyptic number.

It is an amenable number.

1221550073 is a deficient number, since it is larger than the sum of its proper divisors (1).

1221550073 is an equidigital number, since it uses as much as digits as its factorization.

1221550073 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2100, while the sum is 26.

The square root of 1221550073 is about 34950.6805799258. The cubic root of 1221550073 is about 1068.9820793587.

The spelling of 1221550073 in words is "one billion, two hundred twenty-one million, five hundred fifty thousand, seventy-three".