645688211077 has 16 divisors (see below), whose sum is σ = 795397200640. Its totient is φ = 510421606272.

The previous prime is 645688211059. The next prime is 645688211107. The reversal of 645688211077 is 770112886546.

It is a cyclic number.

It is not a de Polignac number, because 645688211077 - 2¹⁹ = 645687686789 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (645688211027) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3039633 + ... + 3245110.

It is an arithmetic number, because the mean of its divisors is an integer number (49712325040).

Almost surely, 2^645688211077 is an apocalyptic number.

It is an amenable number.

645688211077 is a deficient number, since it is larger than the sum of its proper divisors (149708989563).

645688211077 is a wasteful number, since it uses less digits than its factorization.

645688211077 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6285892.

The product of its (nonzero) digits is 4515840, while the sum is 55.

The spelling of 645688211077 in words is "six hundred forty-five billion, six hundred eighty-eight million, two hundred eleven thousand, seventy-seven".