645869074 has 4 divisors (see below), whose sum is σ = 968803614. Its totient is φ = 322934536.

The previous prime is 645869069. The next prime is 645869087. The reversal of 645869074 is 470968546.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 470968546 = 2 ⋅235484273.

It can be written as a sum of positive squares in only one way, i.e., 376088449 + 269780625 = 19393^2 + 16425^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 161467267 + ... + 161467270.

Almost surely, 2^645869074 is an apocalyptic number.

645869074 is a deficient number, since it is larger than the sum of its proper divisors (322934540).

645869074 is a wasteful number, since it uses less digits than its factorization.

645869074 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 322934539.

The product of its (nonzero) digits is 1451520, while the sum is 49.

The square root of 645869074 is about 25413.9543164774. The cubic root of 645869074 is about 864.4001427647.

The spelling of 645869074 in words is "six hundred forty-five million, eight hundred sixty-nine thousand, seventy-four".