645606434131 has 4 divisors (see below), whose sum is σ = 645612363000. Its totient is φ = 645600505264.

The previous prime is 645606434111. The next prime is 645606434153. The reversal of 645606434131 is 131434606546.

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

It is a cyclic number.

It is not a de Polignac number, because 645606434131 - 2¹¹ = 645606432083 is a prime.

It is a super-2 number, since 2×645606434131² (a number of 24 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (645606434101) 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 3 ways as a sum of consecutive naturals, for example, 2797981 + ... + 3019918.

It is an arithmetic number, because the mean of its divisors is an integer number (161403090750).

Almost surely, 2^645606434131 is an apocalyptic number.

645606434131 is a deficient number, since it is larger than the sum of its proper divisors (5928869).

645606434131 is a wasteful number, since it uses less digits than its factorization.

645606434131 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5928868.

The product of its (nonzero) digits is 622080, while the sum is 43.

The spelling of 645606434131 in words is "six hundred forty-five billion, six hundred six million, four hundred thirty-four thousand, one hundred thirty-one".