1645420739 has 2 divisors, whose sum is σ = 1645420740. Its totient is φ = 1645420738.

The previous prime is 1645420717. The next prime is 1645420753. The reversal of 1645420739 is 9370245461.

It is a strong prime.

It is an emirp because it is prime and its reverse (9370245461) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1645420739 - 2¹⁶ = 1645355203 is a prime.

It is a super-2 number, since 2×1645420739² = 5414818816662612242, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 1645420696 and 1645420705.

It is not a weakly prime, because it can be changed into another prime (1645420709) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 822710369 + 822710370.

It is an arithmetic number, because the mean of its divisors is an integer number (822710370).

Almost surely, 2^1645420739 is an apocalyptic number.

1645420739 is a deficient number, since it is larger than the sum of its proper divisors (1).

1645420739 is an equidigital number, since it uses as much as digits as its factorization.

1645420739 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 181440, while the sum is 41.

The square root of 1645420739 is about 40563.7860535725. The cubic root of 1645420739 is about 1180.5715748116.

The spelling of 1645420739 in words is "one billion, six hundred forty-five million, four hundred twenty thousand, seven hundred thirty-nine".