1397112781 has 2 divisors, whose sum is σ = 1397112782. Its totient is φ = 1397112780.

The previous prime is 1397112757. The next prime is 1397112799. The reversal of 1397112781 is 1872117931.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1343222500 + 53890281 = 36650^2 + 7341^2 .

It is a cyclic number.

It is not a de Polignac number, because 1397112781 - 2¹⁷ = 1396981709 is a prime.

It is a super-2 number, since 2×1397112781² = 3903848245667107922, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1397112281) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 698556390 + 698556391.

It is an arithmetic number, because the mean of its divisors is an integer number (698556391).

Almost surely, 2^1397112781 is an apocalyptic number.

It is an amenable number.

1397112781 is a deficient number, since it is larger than the sum of its proper divisors (1).

1397112781 is an equidigital number, since it uses as much as digits as its factorization.

1397112781 is an evil number, because the sum of its binary digits is even.

The product of its digits is 21168, while the sum is 40.

The square root of 1397112781 is about 37377.9718684682. The cubic root of 1397112781 is about 1117.9193890204.

The spelling of 1397112781 in words is "one billion, three hundred ninety-seven million, one hundred twelve thousand, seven hundred eighty-one".