1225355781 has 16 divisors (see below), whose sum is σ = 1760885504. Its totient is φ = 753465024.

The previous prime is 1225355779. The next prime is 1225355819. The reversal of 1225355781 is 1875535221.

It is not a de Polignac number, because 1225355781 - 2¹ = 1225355779 is a prime.

It is a super-2 number, since 2×1225355781² = 3002993580060239922, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (39).

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1225355741) 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, 39915 + ... + 63591.

It is an arithmetic number, because the mean of its divisors is an integer number (110055344).

Almost surely, 2^1225355781 is an apocalyptic number.

It is an amenable number.

1225355781 is a deficient number, since it is larger than the sum of its proper divisors (535529723).

1225355781 is a wasteful number, since it uses less digits than its factorization.

1225355781 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 25020.

The product of its digits is 84000, while the sum is 39.

The square root of 1225355781 is about 35005.0822167296. The cubic root of 1225355781 is about 1070.0910572637.

The spelling of 1225355781 in words is "one billion, two hundred twenty-five million, three hundred fifty-five thousand, seven hundred eighty-one".