651611440 has 80 divisors (see below), whose sum is σ = 1609807680. Its totient is φ = 244823040.

The previous prime is 651611437. The next prime is 651611497. The reversal of 651611440 is 44116156.

651611440 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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

It is a junction number, because it is equal to n+sod(n) for n = 651611399 and 651611408.

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, 82045 + ... + 89635.

It is an arithmetic number, because the mean of its divisors is an integer number (20122596).

Almost surely, 2^651611440 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 651611440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (804903840).

651611440 is an abundant number, since it is smaller than the sum of its proper divisors (958196240).

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

651611440 is a wasteful number, since it uses less digits than its factorization.

651611440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7670 (or 7664 counting only the distinct ones).

The product of its (nonzero) digits is 2880, while the sum is 28.

The square root of 651611440 is about 25526.6809436715. The cubic root of 651611440 is about 866.9543568246.

Adding to 651611440 its reverse (44116156), we get a palindrome (695727596).

It can be divided in two parts, 6516 and 11440, that added together give a square (17956 = 134²).

The spelling of 651611440 in words is "six hundred fifty-one million, six hundred eleven thousand, four hundred forty".