63421367981 has 2 divisors, whose sum is σ = 63421367982. Its totient is φ = 63421367980.

The previous prime is 63421367959. The next prime is 63421367983. The reversal of 63421367981 is 18976312436.

63421367981 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 48571752100 + 14849615881 = 220390^2 + 121859^2 .

It is a cyclic number.

It is not a de Polignac number, because 63421367981 - 2²⁶ = 63354259117 is a prime.

It is a super-2 number, since 2×63421367981² (a number of 22 digits) contains 22 as substring.

Together with 63421367983, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (63421367983) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 31710683990 + 31710683991.

It is an arithmetic number, because the mean of its divisors is an integer number (31710683991).

Almost surely, 2^63421367981 is an apocalyptic number.

It is an amenable number.

63421367981 is a deficient number, since it is larger than the sum of its proper divisors (1).

63421367981 is an equidigital number, since it uses as much as digits as its factorization.

63421367981 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1306368, while the sum is 50.

The spelling of 63421367981 in words is "sixty-three billion, four hundred twenty-one million, three hundred sixty-seven thousand, nine hundred eighty-one".