63305981 has 2 divisors, whose sum is σ = 63305982. Its totient is φ = 63305980.

The previous prime is 63305971. The next prime is 63305989. The reversal of 63305981 is 18950336.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 62568100 + 737881 = 7910^2 + 859^2 .

It is a cyclic number.

It is not a de Polignac number, because 63305981 - 2⁶ = 63305917 is a prime.

It is a super-2 number, since 2×63305981² = 8015294460744722, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (63305989) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 31652990 + 31652991.

It is an arithmetic number, because the mean of its divisors is an integer number (31652991).

Almost surely, 2^63305981 is an apocalyptic number.

It is an amenable number.

63305981 is a deficient number, since it is larger than the sum of its proper divisors (1).

63305981 is an equidigital number, since it uses as much as digits as its factorization.

63305981 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 19440, while the sum is 35.

The square root of 63305981 is about 7956.5055771991. The cubic root of 63305981 is about 398.5488689965.

The spelling of 63305981 in words is "sixty-three million, three hundred five thousand, nine hundred eighty-one".