651121 has 4 divisors (see below), whose sum is σ = 667044. Its totient is φ = 635200.

The previous prime is 651109. The next prime is 651127. The reversal of 651121 is 121156.

It is a happy number.

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 314721 + 336400 = 561^2 + 580^2 .

It is a cyclic number.

It is not a de Polignac number, because 651121 - 2⁹ = 650609 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 651095 and 651104.

It is not an unprimeable number, because it can be changed into a prime (651127) by changing a digit.

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, 7900 + ... + 7981.

It is an arithmetic number, because the mean of its divisors is an integer number (166761).

2⁶⁵¹¹²¹ is an apocalyptic number.

It is an amenable number.

651121 is a deficient number, since it is larger than the sum of its proper divisors (15923).

651121 is a wasteful number, since it uses less digits than its factorization.

651121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15922.

The product of its digits is 60, while the sum is 16.

The square root of 651121 is about 806.9206900309. The cubic root of 651121 is about 86.6736795772.

Adding to 651121 its reverse (121156), we get a palindrome (772277).

The spelling of 651121 in words is "six hundred fifty-one thousand, one hundred twenty-one".