651561440 has 24 divisors (see below), whose sum is σ = 1539314280. Its totient is φ = 260624512.

The previous prime is 651561439. The next prime is 651561481. The reversal of 651561440 is 44165156.

651561440 is digitally balanced in base 6, because in such base it contains all the possibile digits an equal number of times.

It is a Harshad number since it is a multiple of its sum of digits (32).

It is a junction number, because it is equal to n+sod(n) for n = 651561397 and 651561406.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2035970 + ... + 2036289.

It is an arithmetic number, because the mean of its divisors is an integer number (64138095).

Almost surely, 2^651561440 is an apocalyptic number.

It is an amenable number.

651561440 is an abundant number, since it is smaller than the sum of its proper divisors (887752840).

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

651561440 is a wasteful number, since it uses less digits than its factorization.

651561440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4072274 (or 4072266 counting only the distinct ones).

The product of its (nonzero) digits is 14400, while the sum is 32.

The square root of 651561440 is about 25525.7015574499. The cubic root of 651561440 is about 866.9321816325.

The spelling of 651561440 in words is "six hundred fifty-one million, five hundred sixty-one thousand, four hundred forty".