645155426 has 4 divisors (see below), whose sum is σ = 967733142. Its totient is φ = 322577712.

The previous prime is 645155387. The next prime is 645155443. The reversal of 645155426 is 624551546.

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., 645109201 + 46225 = 25399^2 + 215^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 645155426.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 161288855 + ... + 161288858.

Almost surely, 2^645155426 is an apocalyptic number.

645155426 is a deficient number, since it is larger than the sum of its proper divisors (322577716).

645155426 is a wasteful number, since it uses less digits than its factorization.

645155426 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 322577715.

The product of its digits is 144000, while the sum is 38.

The square root of 645155426 is about 25399.9099604703. The cubic root of 645155426 is about 864.0816546984.

The spelling of 645155426 in words is "six hundred forty-five million, one hundred fifty-five thousand, four hundred twenty-six".