1396921381 has 2 divisors, whose sum is σ = 1396921382. Its totient is φ = 1396921380.

The previous prime is 1396921367. The next prime is 1396921397. The reversal of 1396921381 is 1831296931.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 751253281 + 645668100 = 27409^2 + 25410^2 .

It is a cyclic number.

It is not a de Polignac number, because 1396921381 - 2¹¹ = 1396919333 is a prime.

It is a super-2 number, since 2×1396921381² = 3902778689389894322, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1396921321) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 698460690 + 698460691.

It is an arithmetic number, because the mean of its divisors is an integer number (698460691).

Almost surely, 2^1396921381 is an apocalyptic number.

It is an amenable number.

1396921381 is a deficient number, since it is larger than the sum of its proper divisors (1).

1396921381 is an equidigital number, since it uses as much as digits as its factorization.

1396921381 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 69984, while the sum is 43.

The square root of 1396921381 is about 37375.4114492403. The cubic root of 1396921381 is about 1117.8683362240.

The spelling of 1396921381 in words is "one billion, three hundred ninety-six million, nine hundred twenty-one thousand, three hundred eighty-one".