645435026 has 4 divisors (see below), whose sum is σ = 968152542. Its totient is φ = 322717512.

The previous prime is 645435019. The next prime is 645435061. The reversal of 645435026 is 620534546.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 642369025 + 3066001 = 25345^2 + 1751^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 161358755 + ... + 161358758.

Almost surely, 2^645435026 is an apocalyptic number.

645435026 is a deficient number, since it is larger than the sum of its proper divisors (322717516).

645435026 is a wasteful number, since it uses less digits than its factorization.

645435026 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 322717515.

The product of its (nonzero) digits is 86400, while the sum is 35.

The square root of 645435026 is about 25405.4133207866. The cubic root of 645435026 is about 864.2064630407.

The spelling of 645435026 in words is "six hundred forty-five million, four hundred thirty-five thousand, twenty-six".