645077746 has 4 divisors (see below), whose sum is σ = 967616622. Its totient is φ = 322538872.

The previous prime is 645077707. The next prime is 645077749. The reversal of 645077746 is 647770546.

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., 640646721 + 4431025 = 25311^2 + 2105^2 .

It is a super-2 number, since 2×645077746² = 832250596768881032, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 645077696 and 645077705.

It is not an unprimeable number, because it can be changed into a prime (645077749) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 161269435 + ... + 161269438.

Almost surely, 2^645077746 is an apocalyptic number.

645077746 is a deficient number, since it is larger than the sum of its proper divisors (322538876).

645077746 is a wasteful number, since it uses less digits than its factorization.

645077746 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 322538875.

The product of its (nonzero) digits is 987840, while the sum is 46.

The square root of 645077746 is about 25398.3807751597. The cubic root of 645077746 is about 864.0469733621.

The spelling of 645077746 in words is "six hundred forty-five million, seventy-seven thousand, seven hundred forty-six".