645877742 has 4 divisors (see below), whose sum is σ = 968816616. Its totient is φ = 322938870.

The previous prime is 645877741. The next prime is 645877801. The reversal of 645877742 is 247778546.

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

It is a super-2 number, since 2×645877742² = 834316115222037128, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (645877741) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 161469434 + ... + 161469437.

It is an arithmetic number, because the mean of its divisors is an integer number (242204154).

Almost surely, 2^645877742 is an apocalyptic number.

645877742 is a deficient number, since it is larger than the sum of its proper divisors (322938874).

645877742 is a wasteful number, since it uses less digits than its factorization.

645877742 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 322938873.

The product of its digits is 2634240, while the sum is 50.

The square root of 645877742 is about 25414.1248521369. The cubic root of 645877742 is about 864.4040096923.

The spelling of 645877742 in words is "six hundred forty-five million, eight hundred seventy-seven thousand, seven hundred forty-two".