645616742 has 4 divisors (see below), whose sum is σ = 968425116. Its totient is φ = 322808370.

The previous prime is 645616711. The next prime is 645616801. The reversal of 645616742 is 247616546.

It is a happy number.

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

It is a self number, because there is not a number n which added to its sum of digits gives 645616742.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 161404184 + ... + 161404187.

It is an arithmetic number, because the mean of its divisors is an integer number (242106279).

Almost surely, 2^645616742 is an apocalyptic number.

645616742 is a deficient number, since it is larger than the sum of its proper divisors (322808374).

645616742 is a wasteful number, since it uses less digits than its factorization.

645616742 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 322808373.

The product of its digits is 241920, while the sum is 41.

The square root of 645616742 is about 25408.9893935198. The cubic root of 645616742 is about 864.2875584259.

The spelling of 645616742 in words is "six hundred forty-five million, six hundred sixteen thousand, seven hundred forty-two".