1390318821 has 6 divisors (see below), whose sum is σ = 2008238310. Its totient is φ = 926879208.

The previous prime is 1390318819. The next prime is 1390318849. The reversal of 1390318821 is 1288130931.

It can be written as a sum of positive squares in only one way, i.e., 768065796 + 622253025 = 27714^2 + 24945^2 .

It is not a de Polignac number, because 1390318821 - 2¹ = 1390318819 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1390318861) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 77239926 + ... + 77239943.

It is an arithmetic number, because the mean of its divisors is an integer number (334706385).

Almost surely, 2^1390318821 is an apocalyptic number.

It is an amenable number.

1390318821 is a deficient number, since it is larger than the sum of its proper divisors (617919489).

1390318821 is a wasteful number, since it uses less digits than its factorization.

1390318821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 154479875 (or 154479872 counting only the distinct ones).

The product of its (nonzero) digits is 10368, while the sum is 36.

The square root of 1390318821 is about 37286.9792420893. The cubic root of 1390318821 is about 1116.1043496098.

The spelling of 1390318821 in words is "one billion, three hundred ninety million, three hundred eighteen thousand, eight hundred twenty-one".