645096591 has 12 divisors (see below), whose sum is σ = 956990632. Its totient is φ = 418440816.

The previous prime is 645096589. The next prime is 645096593. The reversal of 645096591 is 195690546.

It is a happy number.

645096591 is a `hidden beast` number, since 6 + 4 + 50 + 9 + 6 + 591 = 666.

It is an interprime number because it is at equal distance from previous prime (645096589) and next prime (645096593).

It is not a de Polignac number, because 645096591 - 2¹ = 645096589 is a prime.

It is a super-2 number, since 2×645096591² = 832299223439642562, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (645096593) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 968281 + ... + 968946.

Almost surely, 2^645096591 is an apocalyptic number.

645096591 is a deficient number, since it is larger than the sum of its proper divisors (311894041).

645096591 is a wasteful number, since it uses less digits than its factorization.

645096591 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1937270 (or 1937267 counting only the distinct ones).

The product of its (nonzero) digits is 291600, while the sum is 45.

The square root of 645096591 is about 25398.7517606673. The cubic root of 645096591 is about 864.0553872350.

It can be divided in two parts, 6450 and 96591, that added together give a square (103041 = 321²).

The spelling of 645096591 in words is "six hundred forty-five million, ninety-six thousand, five hundred ninety-one".