651009840 has 80 divisors (see below), whose sum is σ = 2173381728. Its totient is φ = 160247808.

The previous prime is 651009829. The next prime is 651009847. The reversal of 651009840 is 48900156.

It is a tau number, because it is divible by the number of its divisors (80).

It is not an unprimeable number, because it can be changed into a prime (651009847) 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, 101209 + ... + 107448.

Almost surely, 2^651009840 is an apocalyptic number.

651009840 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

651009840 is an abundant number, since it is smaller than the sum of its proper divisors (1522371888).

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

651009840 is a wasteful number, since it uses less digits than its factorization.

651009840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 208686 (or 208680 counting only the distinct ones).

The product of its (nonzero) digits is 8640, while the sum is 33.

The square root of 651009840 is about 25514.8944736207. The cubic root of 651009840 is about 866.6874695861.

Adding to 651009840 its reverse (48900156), we get a palindrome (699909996).

The spelling of 651009840 in words is "six hundred fifty-one million, nine thousand, eight hundred forty".