645400547045 has 4 divisors (see below), whose sum is σ = 774480656460. Its totient is φ = 516320437632.

The previous prime is 645400547009. The next prime is 645400547063. The reversal of 645400547045 is 540745004546.

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 92611271041 + 552789276004 = 304321^2 + 743498^2 .

It is a cyclic number.

It is not a de Polignac number, because 645400547045 - 2¹⁴ = 645400530661 is a prime.

It is a super-2 number, since 2×645400547045² (a number of 24 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 645400546987 and 645400547005.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 64540054700 + ... + 64540054709.

It is an arithmetic number, because the mean of its divisors is an integer number (193620164115).

Almost surely, 2^645400547045 is an apocalyptic number.

It is an amenable number.

645400547045 is a deficient number, since it is larger than the sum of its proper divisors (129080109415).

645400547045 is a wasteful number, since it uses less digits than its factorization.

645400547045 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 129080109414.

The product of its (nonzero) digits is 1344000, while the sum is 44.

The spelling of 645400547045 in words is "six hundred forty-five billion, four hundred million, five hundred forty-seven thousand, forty-five".