1221001051 has 2 divisors, whose sum is σ = 1221001052. Its totient is φ = 1221001050.

The previous prime is 1221000997. The next prime is 1221001063. The reversal of 1221001051 is 1501001221.

It is a strong prime.

It is an emirp because it is prime and its reverse (1501001221) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1221001051 - 2²¹ = 1218903899 is a prime.

It is not a weakly prime, because it can be changed into another prime (1221001091) 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, 610500525 + 610500526.

It is an arithmetic number, because the mean of its divisors is an integer number (610500526).

Almost surely, 2^1221001051 is an apocalyptic number.

1221001051 is a deficient number, since it is larger than the sum of its proper divisors (1).

1221001051 is an equidigital number, since it uses as much as digits as its factorization.

1221001051 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 20, while the sum is 13.

The square root of 1221001051 is about 34942.8254581681. The cubic root of 1221001051 is about 1068.8219051014.

Adding to 1221001051 its reverse (1501001221), we get a palindrome (2722002272).

The spelling of 1221001051 in words is "one billion, two hundred twenty-one million, one thousand, fifty-one".