651491 has 8 divisors (see below), whose sum is σ = 726480. Its totient is φ = 580608.

The previous prime is 651487. The next prime is 651503. The reversal of 651491 is 194156.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 651491 - 2² = 651487 is a prime.

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 651491.

It is not an unprimeable number, because it can be changed into a prime (651401) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 686 + ... + 1331.

It is an arithmetic number, because the mean of its divisors is an integer number (90810).

2⁶⁵¹⁴⁹¹ is an apocalyptic number.

651491 is a deficient number, since it is larger than the sum of its proper divisors (74989).

651491 is a wasteful number, since it uses less digits than its factorization.

651491 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2053.

The product of its digits is 1080, while the sum is 26.

The square root of 651491 is about 807.1499241157. The cubic root of 651491 is about 86.6900939297.

The spelling of 651491 in words is "six hundred fifty-one thousand, four hundred ninety-one".