651878 has 4 divisors (see below), whose sum is σ = 977820. Its totient is φ = 325938.

The previous prime is 651877. The next prime is 651881. The reversal of 651878 is 878156.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (651877) 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 as a sum of consecutive naturals, namely, 162968 + ... + 162971.

It is an arithmetic number, because the mean of its divisors is an integer number (244455).

2⁶⁵¹⁸⁷⁸ is an apocalyptic number.

651878 is a deficient number, since it is larger than the sum of its proper divisors (325942).

651878 is a wasteful number, since it uses less digits than its factorization.

651878 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 325941.

The product of its digits is 13440, while the sum is 35.

The square root of 651878 is about 807.3896209390. The cubic root of 651878 is about 86.7072558069.

The spelling of 651878 in words is "six hundred fifty-one thousand, eight hundred seventy-eight".