651891 has 16 divisors (see below), whose sum is σ = 921600. Its totient is φ = 409248.

The previous prime is 651881. The next prime is 651901. The reversal of 651891 is 198156.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (651881) and next prime (651901).

It is not a de Polignac number, because 651891 - 2¹¹ = 649843 is a prime.

It is not an unprimeable number, because it can be changed into a prime (651811) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 5070 + ... + 5196.

It is an arithmetic number, because the mean of its divisors is an integer number (57600).

2⁶⁵¹⁸⁹¹ is an apocalyptic number.

651891 is a deficient number, since it is larger than the sum of its proper divisors (269709).

651891 is a wasteful number, since it uses less digits than its factorization.

651891 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 218.

The product of its digits is 2160, while the sum is 30.

The square root of 651891 is about 807.3976715349. The cubic root of 651891 is about 86.7078321861.

The spelling of 651891 in words is "six hundred fifty-one thousand, eight hundred ninety-one".