1221801503 has 8 divisors (see below), whose sum is σ = 1320281088. Its totient is φ = 1123964064.

The previous prime is 1221801487. The next prime is 1221801541. The reversal of 1221801503 is 3051081221.

It is a happy number.

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 1221801503 - 2⁴ = 1221801487 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 (1221801703) 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, 156575 + ... + 164192.

It is an arithmetic number, because the mean of its divisors is an integer number (165035136).

Almost surely, 2^1221801503 is an apocalyptic number.

1221801503 is a gapful number since it is divisible by the number (13) formed by its first and last digit.

1221801503 is a deficient number, since it is larger than the sum of its proper divisors (98479585).

1221801503 is a wasteful number, since it uses less digits than its factorization.

1221801503 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 321073.

The product of its (nonzero) digits is 480, while the sum is 23.

The square root of 1221801503 is about 34954.2773205226. The cubic root of 1221801503 is about 1069.0554167060.

Adding to 1221801503 its reverse (3051081221), we get a palindrome (4272882724).

The spelling of 1221801503 in words is "one billion, two hundred twenty-one million, eight hundred one thousand, five hundred three".