645178153 has 4 divisors (see below), whose sum is σ = 649451008. Its totient is φ = 640905300.

The previous prime is 645178103. The next prime is 645178159. The reversal of 645178153 is 351871546.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 645178153 - 2⁹ = 645177641 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (645178159) 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, 2136201 + ... + 2136502.

It is an arithmetic number, because the mean of its divisors is an integer number (162362752).

Almost surely, 2^645178153 is an apocalyptic number.

It is an amenable number.

645178153 is a deficient number, since it is larger than the sum of its proper divisors (4272855).

645178153 is a wasteful number, since it uses less digits than its factorization.

645178153 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4272854.

The product of its digits is 100800, while the sum is 40.

The square root of 645178153 is about 25400.3573400061. The cubic root of 645178153 is about 864.0918009631.

The spelling of 645178153 in words is "six hundred forty-five million, one hundred seventy-eight thousand, one hundred fifty-three".