651750661 has 4 divisors (see below), whose sum is σ = 651824172. Its totient is φ = 651677152.

The previous prime is 651750647. The next prime is 651750667. The reversal of 651750661 is 166057156.

651750661 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 505800100 + 145950561 = 22490^2 + 12081^2 .

It is a cyclic number.

It is not a de Polignac number, because 651750661 - 2¹¹ = 651748613 is a prime.

It is a super-2 number, since 2×651750661² = 849557848227873842, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 651750661.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (651750667) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 21286 + ... + 41911.

It is an arithmetic number, because the mean of its divisors is an integer number (162956043).

Almost surely, 2^651750661 is an apocalyptic number.

It is an amenable number.

651750661 is a deficient number, since it is larger than the sum of its proper divisors (73511).

651750661 is a wasteful number, since it uses less digits than its factorization.

651750661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 73510.

The product of its (nonzero) digits is 37800, while the sum is 37.

The square root of 651750661 is about 25529.4077682973. The cubic root of 651750661 is about 867.0160958970.

The spelling of 651750661 in words is "six hundred fifty-one million, seven hundred fifty thousand, six hundred sixty-one".