1981225447 has 2 divisors, whose sum is σ = 1981225448. Its totient is φ = 1981225446.

The previous prime is 1981225423. The next prime is 1981225471. The reversal of 1981225447 is 7445221891.

It is a balanced prime because it is at equal distance from previous prime (1981225423) and next prime (1981225471).

It is a cyclic number.

It is not a de Polignac number, because 1981225447 - 2⁷ = 1981225319 is a prime.

It is a super-3 number, since 3×1981225447³ (a number of 29 digits) contains 333 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1981225417) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 990612723 + 990612724.

It is an arithmetic number, because the mean of its divisors is an integer number (990612724).

Almost surely, 2^1981225447 is an apocalyptic number.

1981225447 is a deficient number, since it is larger than the sum of its proper divisors (1).

1981225447 is an equidigital number, since it uses as much as digits as its factorization.

1981225447 is an evil number, because the sum of its binary digits is even.

The product of its digits is 161280, while the sum is 43.

The square root of 1981225447 is about 44510.9587292837. The cubic root of 1981225447 is about 1255.9662399052.

The spelling of 1981225447 in words is "one billion, nine hundred eighty-one million, two hundred twenty-five thousand, four hundred forty-seven".