1645342543 has 4 divisors (see below), whose sum is σ = 1771907368. Its totient is φ = 1518777720.

The previous prime is 1645342541. The next prime is 1645342549. The reversal of 1645342543 is 3452435461.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 3452435461 = 151 ⋅22863811.

It is a cyclic number.

It is not a de Polignac number, because 1645342543 - 2¹ = 1645342541 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1645342541) 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 3 ways as a sum of consecutive naturals, for example, 63282393 + ... + 63282418.

It is an arithmetic number, because the mean of its divisors is an integer number (442976842).

Almost surely, 2^1645342543 is an apocalyptic number.

1645342543 is a gapful number since it is divisible by the number (13) formed by its first and last digit.

1645342543 is a deficient number, since it is larger than the sum of its proper divisors (126564825).

1645342543 is a wasteful number, since it uses less digits than its factorization.

1645342543 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 126564824.

The product of its digits is 172800, while the sum is 37.

The square root of 1645342543 is about 40562.8221774570. The cubic root of 1645342543 is about 1180.5528729208.

It can be divided in two parts, 16453 and 42543, that added together give a triangular number (58996 = T₃₄₃).

The spelling of 1645342543 in words is "one billion, six hundred forty-five million, three hundred forty-two thousand, five hundred forty-three".