645178746 has 16 divisors (see below), whose sum is σ = 1295157600. Its totient is φ = 214259568.

The previous prime is 645178741. The next prime is 645178753. The reversal of 645178746 is 647871546.

It is a super-2 number, since 2×645178746² = 832511228580265032, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 645178695 and 645178704.

It is not an unprimeable number, because it can be changed into a prime (645178741) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 198256 + ... + 201483.

It is an arithmetic number, because the mean of its divisors is an integer number (80947350).

Almost surely, 2^645178746 is an apocalyptic number.

645178746 is an abundant number, since it is smaller than the sum of its proper divisors (649978854).

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

645178746 is a wasteful number, since it uses less digits than its factorization.

645178746 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 400013.

The product of its digits is 1128960, while the sum is 48.

The square root of 645178746 is about 25400.3690130675. The cubic root of 645178746 is about 864.0920656995.

The spelling of 645178746 in words is "six hundred forty-five million, one hundred seventy-eight thousand, seven hundred forty-six".