1221251003 has 16 divisors (see below), whose sum is σ = 1411976640. Its totient is φ = 1034643456.

The previous prime is 1221250997. The next prime is 1221251021. The reversal of 1221251003 is 3001521221.

It is a happy number.

It is not a de Polignac number, because 1221251003 - 2¹⁰ = 1221249979 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1221251203) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 312083 + ... + 315971.

It is an arithmetic number, because the mean of its divisors is an integer number (88248540).

Almost surely, 2^1221251003 is an apocalyptic number.

1221251003 is a deficient number, since it is larger than the sum of its proper divisors (190725637).

1221251003 is a wasteful number, since it uses less digits than its factorization.

1221251003 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4406.

The product of its (nonzero) digits is 120, while the sum is 17.

The square root of 1221251003 is about 34946.4018605636. The cubic root of 1221251003 is about 1068.8948332246.

Adding to 1221251003 its reverse (3001521221), we get a palindrome (4222772224).

The spelling of 1221251003 in words is "one billion, two hundred twenty-one million, two hundred fifty-one thousand, three".