1981006403 has 2 divisors, whose sum is σ = 1981006404. Its totient is φ = 1981006402.

The previous prime is 1981006397. The next prime is 1981006421. The reversal of 1981006403 is 3046001891.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 1981006403 - 2⁸ = 1981006147 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1981006403.

It is not a weakly prime, because it can be changed into another prime (1981006303) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 990503201 + 990503202.

It is an arithmetic number, because the mean of its divisors is an integer number (990503202).

Almost surely, 2^1981006403 is an apocalyptic number.

1981006403 is a deficient number, since it is larger than the sum of its proper divisors (1).

1981006403 is an equidigital number, since it uses as much as digits as its factorization.

1981006403 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 5184, while the sum is 32.

The square root of 1981006403 is about 44508.4980986777. The cubic root of 1981006403 is about 1255.9199517171.

The spelling of 1981006403 in words is "one billion, nine hundred eighty-one million, six thousand, four hundred three".