645076644 has 48 divisors (see below), whose sum is σ = 1558233600. Its totient is φ = 207486720.

The previous prime is 645076643. The next prime is 645076651. The reversal of 645076644 is 446670546.

It is a happy number.

It is a super-2 number, since 2×645076644² = 832247753268605472, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 645076596 and 645076605.

It is not an unprimeable number, because it can be changed into a prime (645076643) 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, 136432 + ... + 141080.

It is an arithmetic number, because the mean of its divisors is an integer number (32463200).

Almost surely, 2^645076644 is an apocalyptic number.

It is an amenable number.

645076644 is an abundant number, since it is smaller than the sum of its proper divisors (913156956).

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

645076644 is a wasteful number, since it uses less digits than its factorization.

645076644 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5060 (or 5058 counting only the distinct ones).

The product of its (nonzero) digits is 483840, while the sum is 42.

The square root of 645076644 is about 25398.3590808540. The cubic root of 645076644 is about 864.0464813385.

The spelling of 645076644 in words is "six hundred forty-five million, seventy-six thousand, six hundred forty-four".