1263290681 has 2 divisors, whose sum is σ = 1263290682. Its totient is φ = 1263290680.

The previous prime is 1263290657. The next prime is 1263290687. The reversal of 1263290681 is 1860923621.

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., 1035552400 + 227738281 = 32180^2 + 15091^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1263290681 is a prime.

It is a super-2 number, since 2×1263290681² = 3191806689402887522, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (1263290687) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 631645340 + 631645341.

It is an arithmetic number, because the mean of its divisors is an integer number (631645341).

Almost surely, 2^1263290681 is an apocalyptic number.

It is an amenable number.

1263290681 is a deficient number, since it is larger than the sum of its proper divisors (1).

1263290681 is an equidigital number, since it uses as much as digits as its factorization.

1263290681 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 31104, while the sum is 38.

The square root of 1263290681 is about 35542.8006915606. The cubic root of 1263290681 is about 1081.0217471078.

The spelling of 1263290681 in words is "one billion, two hundred sixty-three million, two hundred ninety thousand, six hundred eighty-one".