1221266351 has 8 divisors (see below), whose sum is σ = 1275124704. Its totient is φ = 1167471360.

The previous prime is 1221266329. The next prime is 1221266381. The reversal of 1221266351 is 1536621221.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 1221266351 - 2¹⁸ = 1221004207 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 (1221266381) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 25931 + ... + 55811.

It is an arithmetic number, because the mean of its divisors is an integer number (159390588).

Almost surely, 2^1221266351 is an apocalyptic number.

1221266351 is a deficient number, since it is larger than the sum of its proper divisors (53858353).

1221266351 is a wasteful number, since it uses less digits than its factorization.

1221266351 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 31681.

The product of its digits is 4320, while the sum is 29.

The square root of 1221266351 is about 34946.6214532965. The cubic root of 1221266351 is about 1068.8993109634.

Adding to 1221266351 its reverse (1536621221), we get a palindrome (2757887572).

The spelling of 1221266351 in words is "one billion, two hundred twenty-one million, two hundred sixty-six thousand, three hundred fifty-one".