651437540 has 72 divisors (see below), whose sum is σ = 1521674280. Its totient is φ = 233985024.

The previous prime is 651437537. The next prime is 651437543. The reversal of 651437540 is 45734156.

It is an interprime number because it is at equal distance from previous prime (651437537) and next prime (651437543).

It can be written as a sum of positive squares in 12 ways, for example, as 58125376 + 593312164 = 7624^2 + 24358^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 651437540.

It is not an unprimeable number, because it can be changed into a prime (651437543) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 122456 + ... + 127664.

It is an arithmetic number, because the mean of its divisors is an integer number (21134365).

Almost surely, 2^651437540 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 651437540, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (760837140).

651437540 is an abundant number, since it is smaller than the sum of its proper divisors (870236740).

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

651437540 is a wasteful number, since it uses less digits than its factorization.

651437540 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5281 (or 5266 counting only the distinct ones).

The product of its (nonzero) digits is 50400, while the sum is 35.

The square root of 651437540 is about 25523.2744764460. The cubic root of 651437540 is about 866.8772266173.

The spelling of 651437540 in words is "six hundred fifty-one million, four hundred thirty-seven thousand, five hundred forty".