1225362721 has 16 divisors (see below), whose sum is σ = 1345413888. Its totient is φ = 1106784000.

The previous prime is 1225362689. The next prime is 1225362727. The reversal of 1225362721 is 1272635221.

It is a cyclic number.

It is not a de Polignac number, because 1225362721 - 2⁵ = 1225362689 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1225362727) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1747671 + ... + 1748371.

It is an arithmetic number, because the mean of its divisors is an integer number (84088368).

Almost surely, 2^1225362721 is an apocalyptic number.

1225362721 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

1225362721 is a deficient number, since it is larger than the sum of its proper divisors (120051167).

1225362721 is a wasteful number, since it uses less digits than its factorization.

1225362721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1512.

The product of its digits is 10080, while the sum is 31.

The square root of 1225362721 is about 35005.1813450523. The cubic root of 1225362721 is about 1070.0930774710.

Adding to 1225362721 its reverse (1272635221), we get a palindrome (2497997942).

The spelling of 1225362721 in words is "one billion, two hundred twenty-five million, three hundred sixty-two thousand, seven hundred twenty-one".