651961440 has 576 divisors, whose sum is σ = 2656281600. Its totient is φ = 148801536.

The previous prime is 651961433. The next prime is 651961481. The reversal of 651961440 is 44169156.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 651961395 and 651961404.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 13871497 + ... + 13871543.

It is an arithmetic number, because the mean of its divisors is an integer number (4611600).

Almost surely, 2^651961440 is an apocalyptic number.

651961440 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 651961440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1328140800).

651961440 is an abundant number, since it is smaller than the sum of its proper divisors (2004320160).

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

651961440 is a wasteful number, since it uses less digits than its factorization.

651961440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 116 (or 89 counting only the distinct ones).

The product of its (nonzero) digits is 25920, while the sum is 36.

The square root of 651961440 is about 25533.5355953695. The cubic root of 651961440 is about 867.1095514159.

The spelling of 651961440 in words is "six hundred fifty-one million, nine hundred sixty-one thousand, four hundred forty".