1221066151 has 4 divisors (see below), whose sum is σ = 1223822952. Its totient is φ = 1218309352.

The previous prime is 1221066139. The next prime is 1221066163. The reversal of 1221066151 is 1516601221.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is an interprime number because it is at equal distance from previous prime (1221066139) and next prime (1221066163).

It is a cyclic number.

It is not a de Polignac number, because 1221066151 - 2²⁷ = 1086848423 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1221066101) 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 in 3 ways as a sum of consecutive naturals, for example, 1377736 + ... + 1378621.

It is an arithmetic number, because the mean of its divisors is an integer number (305955738).

Almost surely, 2^1221066151 is an apocalyptic number.

1221066151 is a deficient number, since it is larger than the sum of its proper divisors (2756801).

1221066151 is an equidigital number, since it uses as much as digits as its factorization.

1221066151 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2756800.

The product of its (nonzero) digits is 720, while the sum is 25.

The square root of 1221066151 is about 34943.7569674470. The cubic root of 1221066151 is about 1068.8409001900.

Adding to 1221066151 its reverse (1516601221), we get a palindrome (2737667372).

The spelling of 1221066151 in words is "one billion, two hundred twenty-one million, sixty-six thousand, one hundred fifty-one".