651137561 has 4 divisors (see below), whose sum is σ = 655285092. Its totient is φ = 646990032.

The previous prime is 651137533. The next prime is 651137569. The reversal of 651137561 is 165731156.

651137561 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.

It can be written as a sum of positive squares in 2 ways, for example, as 223681936 + 427455625 = 14956^2 + 20675^2 .

It is a cyclic number.

It is not a de Polignac number, because 651137561 - 2⁶ = 651137497 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (651137569) 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, 2073530 + ... + 2073843.

It is an arithmetic number, because the mean of its divisors is an integer number (163821273).

Almost surely, 2^651137561 is an apocalyptic number.

It is an amenable number.

651137561 is a deficient number, since it is larger than the sum of its proper divisors (4147531).

651137561 is a wasteful number, since it uses less digits than its factorization.

651137561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4147530.

The product of its digits is 18900, while the sum is 35.

The square root of 651137561 is about 25517.3972222874. The cubic root of 651137561 is about 866.7441440762.

The spelling of 651137561 in words is "six hundred fifty-one million, one hundred thirty-seven thousand, five hundred sixty-one".