645002040 has 32 divisors (see below), whose sum is σ = 1935006480. Its totient is φ = 172000512.

The previous prime is 645002011. The next prime is 645002069. The reversal of 645002040 is 40200546.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (645002011) and next prime (645002069).

It is a junction number, because it is equal to n+sod(n) for n = 645001998 and 645002016.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2687389 + ... + 2687628.

Almost surely, 2^645002040 is an apocalyptic number.

645002040 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

645002040 is an abundant number, since it is smaller than the sum of its proper divisors (1290004440).

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

645002040 is a wasteful number, since it uses less digits than its factorization.

645002040 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5375031 (or 5375027 counting only the distinct ones).

The product of its (nonzero) digits is 960, while the sum is 21.

The square root of 645002040 is about 25396.8903608296. The cubic root of 645002040 is about 864.0131706669.

Adding to 645002040 its reverse (40200546), we get a palindrome (685202586).

The spelling of 645002040 in words is "six hundred forty-five million, two thousand, forty".