651312640 has 160 divisors (see below), whose sum is σ = 1727969760. Its totient is φ = 233472000.

The previous prime is 651312631. The next prime is 651312671. The reversal of 651312640 is 46213156.

It is a tau number, because it is divible by the number of its divisors (160).

It is a junction number, because it is equal to n+sod(n) for n = 651312599 and 651312608.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2844046 + ... + 2844274.

It is an arithmetic number, because the mean of its divisors is an integer number (10799811).

Almost surely, 2^651312640 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 651312640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (863984880).

651312640 is an abundant number, since it is smaller than the sum of its proper divisors (1076657120).

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

651312640 is a wasteful number, since it uses less digits than its factorization.

651312640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 364 (or 348 counting only the distinct ones).

The product of its (nonzero) digits is 4320, while the sum is 28.

The square root of 651312640 is about 25520.8275727885. The cubic root of 651312640 is about 866.8218210057.

Adding to 651312640 its reverse (46213156), we get a palindrome (697525796).

The spelling of 651312640 in words is "six hundred fifty-one million, three hundred twelve thousand, six hundred forty".