1632817981 has 2 divisors, whose sum is σ = 1632817982. Its totient is φ = 1632817980.

The previous prime is 1632817969. The next prime is 1632817987. The reversal of 1632817981 is 1897182361.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1629413956 + 3404025 = 40366^2 + 1845^2 .

It is a cyclic number.

It is not a de Polignac number, because 1632817981 - 2⁹ = 1632817469 is a prime.

It is a super-2 number, since 2×1632817981² = 5332189118153832722, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1632817987) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 816408990 + 816408991.

It is an arithmetic number, because the mean of its divisors is an integer number (816408991).

Almost surely, 2^1632817981 is an apocalyptic number.

It is an amenable number.

1632817981 is a deficient number, since it is larger than the sum of its proper divisors (1).

1632817981 is an equidigital number, since it uses as much as digits as its factorization.

1632817981 is an evil number, because the sum of its binary digits is even.

The product of its digits is 145152, while the sum is 46.

The square root of 1632817981 is about 40408.1425086578. The cubic root of 1632817981 is about 1177.5497324090.

The spelling of 1632817981 in words is "one billion, six hundred thirty-two million, eight hundred seventeen thousand, nine hundred eighty-one".