645454969 has 8 divisors (see below), whose sum is σ = 658866312. Its totient is φ = 632135040.

The previous prime is 645454961. The next prime is 645454981. The reversal of 645454969 is 969454546.

It can be written as a sum of positive squares in 4 ways, for example, as 103124025 + 542330944 = 10155^2 + 23288^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 645454969 - 2³ = 645454961 is a prime.

It is a super-2 number, since 2×645454969² = 833224234013581922, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (645454961) 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 7 ways as a sum of consecutive naturals, for example, 8494 + ... + 36919.

It is an arithmetic number, because the mean of its divisors is an integer number (82358289).

Almost surely, 2^645454969 is an apocalyptic number.

It is an amenable number.

645454969 is a deficient number, since it is larger than the sum of its proper divisors (13411343).

645454969 is a wasteful number, since it uses less digits than its factorization.

645454969 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 45707.

The product of its digits is 4665600, while the sum is 52.

The square root of 645454969 is about 25405.8058128452. The cubic root of 645454969 is about 864.2153638550.

The spelling of 645454969 in words is "six hundred forty-five million, four hundred fifty-four thousand, nine hundred sixty-nine".