645738136 has 16 divisors (see below), whose sum is σ = 1211059440. Its totient is φ = 322788960.

The previous prime is 645738103. The next prime is 645738139. The reversal of 645738136 is 631837546.

It is a junction number, because it is equal to n+sod(n) for n = 645738092 and 645738101.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (645738139) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 37510 + ... + 51946.

It is an arithmetic number, because the mean of its divisors is an integer number (75691215).

Almost surely, 2^645738136 is an apocalyptic number.

It is an amenable number.

645738136 is a deficient number, since it is larger than the sum of its proper divisors (565321304).

645738136 is a wasteful number, since it uses less digits than its factorization.

645738136 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20034 (or 20030 counting only the distinct ones).

The product of its digits is 362880, while the sum is 43.

The square root of 645738136 is about 25411.3780814815. The cubic root of 645738136 is about 864.3417251071.

The spelling of 645738136 in words is "six hundred forty-five million, seven hundred thirty-eight thousand, one hundred thirty-six".