1642878745 has 4 divisors (see below), whose sum is σ = 1971454500. Its totient is φ = 1314302992.

The previous prime is 1642878673. The next prime is 1642878751. The reversal of 1642878745 is 5478782461.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 5478782461 = 36109 ⋅151729.

It can be written as a sum of positive squares in 2 ways, for example, as 584092224 + 1058786521 = 24168^2 + 32539^2 .

It is a cyclic number.

It is not a de Polignac number, because 1642878745 - 2¹³ = 1642870553 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1642878692 and 1642878701.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 164287870 + ... + 164287879.

It is an arithmetic number, because the mean of its divisors is an integer number (492863625).

Almost surely, 2^1642878745 is an apocalyptic number.

It is an amenable number.

1642878745 is a deficient number, since it is larger than the sum of its proper divisors (328575755).

1642878745 is an equidigital number, since it uses as much as digits as its factorization.

1642878745 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 328575754.

The product of its digits is 3010560, while the sum is 52.

The square root of 1642878745 is about 40532.4406494354. The cubic root of 1642878745 is about 1179.9633104076.

The spelling of 1642878745 in words is "one billion, six hundred forty-two million, eight hundred seventy-eight thousand, seven hundred forty-five".