645201550 has 24 divisors (see below), whose sum is σ = 1371514896. Its totient is φ = 221211840.

The previous prime is 645201467. The next prime is 645201569. The reversal of 645201550 is 55102546.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 921367 + ... + 922066.

It is an arithmetic number, because the mean of its divisors is an integer number (57146454).

Almost surely, 2^645201550 is an apocalyptic number.

645201550 is an abundant number, since it is smaller than the sum of its proper divisors (726313346).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

645201550 is a wasteful number, since it uses less digits than its factorization.

645201550 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1843452 (or 1843447 counting only the distinct ones).

The product of its (nonzero) digits is 6000, while the sum is 28.

The square root of 645201550 is about 25400.8179002173. The cubic root of 645201550 is about 864.1022460944.

It can be divided in two parts, 645 and 201550, that multiplied together give a triangular number (129999750 = T₁₆₁₂₄).

The spelling of 645201550 in words is "six hundred forty-five million, two hundred one thousand, five hundred fifty".