1338847621 has 2 divisors, whose sum is σ = 1338847622. Its totient is φ = 1338847620.

The previous prime is 1338847619. The next prime is 1338847651. The reversal of 1338847621 is 1267488331.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 866654721 + 472192900 = 29439^2 + 21730^2 .

It is a cyclic number.

It is not a de Polignac number, because 1338847621 - 2¹ = 1338847619 is a prime.

Together with 1338847619, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1338847651) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 669423810 + 669423811.

It is an arithmetic number, because the mean of its divisors is an integer number (669423811).

Almost surely, 2^1338847621 is an apocalyptic number.

It is an amenable number.

1338847621 is a deficient number, since it is larger than the sum of its proper divisors (1).

1338847621 is an equidigital number, since it uses as much as digits as its factorization.

1338847621 is an evil number, because the sum of its binary digits is even.

The product of its digits is 193536, while the sum is 43.

The square root of 1338847621 is about 36590.2667522389. The cubic root of 1338847621 is about 1102.1576440889.

It can be divided in two parts, 13388 and 47621, that added together give a square (61009 = 247²).

The spelling of 1338847621 in words is "one billion, three hundred thirty-eight million, eight hundred forty-seven thousand, six hundred twenty-one".