645436331426 has 32 divisors (see below), whose sum is σ = 999016630272. Its totient is φ = 312628498560.

The previous prime is 645436331369. The next prime is 645436331437. The reversal of 645436331426 is 624133634546.

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1970645 + ... + 2274711.

It is an arithmetic number, because the mean of its divisors is an integer number (31219269696).

Almost surely, 2^645436331426 is an apocalyptic number.

645436331426 is a deficient number, since it is larger than the sum of its proper divisors (353580298846).

645436331426 is a wasteful number, since it uses less digits than its factorization.

645436331426 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 304394.

The product of its digits is 3732480, while the sum is 47.

The spelling of 645436331426 in words is "six hundred forty-five billion, four hundred thirty-six million, three hundred thirty-one thousand, four hundred twenty-six".