645540136125199 has 32 divisors (see below), whose sum is σ = 753851558707200. Its totient is φ = 552559807791936.

The previous prime is 645540136125121. The next prime is 645540136125233. The reversal of 645540136125199 is 991521631045546.

It is not a de Polignac number, because 645540136125199 - 2¹³ = 645540136117007 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (645540136122199) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 810360939 + ... + 811157155.

It is an arithmetic number, because the mean of its divisors is an integer number (23557861209600).

Almost surely, 2^{645540136125199} is an apocalyptic number.

645540136125199 is a deficient number, since it is larger than the sum of its proper divisors (108311422582001).

645540136125199 is a wasteful number, since it uses less digits than its factorization.

645540136125199 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 799484 (or 799470 counting only the distinct ones).

The product of its (nonzero) digits is 34992000, while the sum is 61.

The spelling of 645540136125199 in words is "six hundred forty-five trillion, five hundred forty billion, one hundred thirty-six million, one hundred twenty-five thousand, one hundred ninety-nine".