645232361 has 4 divisors (see below), whose sum is σ = 645466500. Its totient is φ = 644998224.

The previous prime is 645232351. The next prime is 645232369. The reversal of 645232361 is 163232546.

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 412090000 + 233142361 = 20300^2 + 15269^2 .

It is a cyclic number.

It is not a de Polignac number, because 645232361 - 2¹⁸ = 644970217 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (645232369) 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, 112886 + ... + 118463.

It is an arithmetic number, because the mean of its divisors is an integer number (161366625).

Almost surely, 2^645232361 is an apocalyptic number.

It is an amenable number.

645232361 is a deficient number, since it is larger than the sum of its proper divisors (234139).

645232361 is a wasteful number, since it uses less digits than its factorization.

645232361 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 234138.

The product of its digits is 25920, while the sum is 32.

The square root of 645232361 is about 25401.4243891952. The cubic root of 645232361 is about 864.1160006752.

The spelling of 645232361 in words is "six hundred forty-five million, two hundred thirty-two thousand, three hundred sixty-one".