1380691021 has 2 divisors, whose sum is σ = 1380691022. Its totient is φ = 1380691020.

The previous prime is 1380691009. The next prime is 1380691049. The reversal of 1380691021 is 1201960831.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1063672996 + 317018025 = 32614^2 + 17805^2 .

It is a cyclic number.

It is not a de Polignac number, because 1380691021 - 2⁷ = 1380690893 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1380691321) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 690345510 + 690345511.

It is an arithmetic number, because the mean of its divisors is an integer number (690345511).

Almost surely, 2^1380691021 is an apocalyptic number.

It is an amenable number.

1380691021 is a deficient number, since it is larger than the sum of its proper divisors (1).

1380691021 is an equidigital number, since it uses as much as digits as its factorization.

1380691021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2592, while the sum is 31.

The square root of 1380691021 is about 37157.6509079893. The cubic root of 1380691021 is about 1113.5220811281.

The spelling of 1380691021 in words is "one billion, three hundred eighty million, six hundred ninety-one thousand, twenty-one".