1390821647 has 2 divisors, whose sum is σ = 1390821648. Its totient is φ = 1390821646.

The previous prime is 1390821637. The next prime is 1390821703. The reversal of 1390821647 is 7461280931.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 1390821647 - 2¹² = 1390817551 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1390821637) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 695410823 + 695410824.

It is an arithmetic number, because the mean of its divisors is an integer number (695410824).

Almost surely, 2^1390821647 is an apocalyptic number.

1390821647 is a deficient number, since it is larger than the sum of its proper divisors (1).

1390821647 is an equidigital number, since it uses as much as digits as its factorization.

1390821647 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 72576, while the sum is 41.

The square root of 1390821647 is about 37293.7212812023. The cubic root of 1390821647 is about 1116.2388843739.

The spelling of 1390821647 in words is "one billion, three hundred ninety million, eight hundred twenty-one thousand, six hundred forty-seven".