645260635020 has 24 divisors (see below), whose sum is σ = 1806729778224. Its totient is φ = 172069502656.

The previous prime is 645260635001. The next prime is 645260635081. The reversal of 645260635020 is 20536062546.

It is a super-2 number, since 2×645260635020² (a number of 24 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 645260635020.

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, 5377171899 + ... + 5377172018.

It is an arithmetic number, because the mean of its divisors is an integer number (75280407426).

Almost surely, 2^645260635020 is an apocalyptic number.

645260635020 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

645260635020 is an abundant number, since it is smaller than the sum of its proper divisors (1161469143204).

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

645260635020 is a wasteful number, since it uses less digits than its factorization.

645260635020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10754343929 (or 10754343927 counting only the distinct ones).

The product of its (nonzero) digits is 259200, while the sum is 39.

Adding to 645260635020 its reverse (20536062546), we get a palindrome (665796697566).

The spelling of 645260635020 in words is "six hundred forty-five billion, two hundred sixty million, six hundred thirty-five thousand, twenty".