645556097 has 4 divisors (see below), whose sum is σ = 651478740. Its totient is φ = 639633456.

The previous prime is 645556061. The next prime is 645556099. The reversal of 645556097 is 790655546.

It is a happy number.

645556097 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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

It can be written as a sum of positive squares in 2 ways, for example, as 193738561 + 451817536 = 13919^2 + 21256^2 .

It is a cyclic number.

It is not a de Polignac number, because 645556097 - 2²² = 641361793 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (645556099) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2961158 + ... + 2961375.

It is an arithmetic number, because the mean of its divisors is an integer number (162869685).

Almost surely, 2^645556097 is an apocalyptic number.

It is an amenable number.

645556097 is a deficient number, since it is larger than the sum of its proper divisors (5922643).

645556097 is a wasteful number, since it uses less digits than its factorization.

645556097 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5922642.

The product of its (nonzero) digits is 1134000, while the sum is 47.

The square root of 645556097 is about 25407.7959886331. The cubic root of 645556097 is about 864.2604957447.

The spelling of 645556097 in words is "six hundred forty-five million, five hundred fifty-six thousand, ninety-seven".