645510055 has 16 divisors (see below), whose sum is σ = 814696704. Its totient is φ = 490314240.

The previous prime is 645510049. The next prime is 645510059. The reversal of 645510055 is 550015546.

It is not a de Polignac number, because 645510055 - 2¹³ = 645501863 is a prime.

It is a super-2 number, since 2×645510055² = 833366462212206050, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (31).

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 645509999 and 645510026.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (645510059) 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, 31074 + ... + 47503.

It is an arithmetic number, because the mean of its divisors is an integer number (50918544).

Almost surely, 2^645510055 is an apocalyptic number.

645510055 is a deficient number, since it is larger than the sum of its proper divisors (169186649).

645510055 is a wasteful number, since it uses less digits than its factorization.

645510055 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 78666.

The product of its (nonzero) digits is 15000, while the sum is 31.

The square root of 645510055 is about 25406.8899119904. The cubic root of 645510055 is about 864.2399484842.

The spelling of 645510055 in words is "six hundred forty-five million, five hundred ten thousand, fifty-five".