645094761 has 16 divisors (see below), whose sum is σ = 869400000. Its totient is φ = 425438208.

The previous prime is 645094759. The next prime is 645094771. The reversal of 645094761 is 167490546.

It is not a de Polignac number, because 645094761 - 2¹ = 645094759 is a prime.

It is a super-2 number, since 2×645094761² = 832294501339294242, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (645094721) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 400125 + ... + 401733.

It is an arithmetic number, because the mean of its divisors is an integer number (54337500).

Almost surely, 2^645094761 is an apocalyptic number.

It is an amenable number.

645094761 is a deficient number, since it is larger than the sum of its proper divisors (224305239).

645094761 is a wasteful number, since it uses less digits than its factorization.

645094761 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2968.

The product of its (nonzero) digits is 181440, while the sum is 42.

The square root of 645094761 is about 25398.7157352493. The cubic root of 645094761 is about 864.0545701880.

The spelling of 645094761 in words is "six hundred forty-five million, ninety-four thousand, seven hundred sixty-one".