651945 has 24 divisors (see below), whose sum is σ = 1214784. Its totient is φ = 297696.

The previous prime is 651943. The next prime is 651971. The reversal of 651945 is 549156.

651945 = 28² + 29² + ... + 125².

It is not a de Polignac number, because 651945 - 2¹ = 651943 is a prime.

It is not an unprimeable number, because it can be changed into a prime (651943) 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 23 ways as a sum of consecutive naturals, for example, 292 + ... + 1178.

It is an arithmetic number, because the mean of its divisors is an integer number (50616).

2⁶⁵¹⁹⁴⁵ is an apocalyptic number.

It is an amenable number.

651945 is a deficient number, since it is larger than the sum of its proper divisors (562839).

651945 is a wasteful number, since it uses less digits than its factorization.

651945 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 909 (or 902 counting only the distinct ones).

The product of its digits is 5400, while the sum is 30.

The square root of 651945 is about 807.4311116126. The cubic root of 651945 is about 86.7102262948.

It can be divided in two parts, 651 and 945, that added together give a triangular number (1596 = T₅₆).

The spelling of 651945 in words is "six hundred fifty-one thousand, nine hundred forty-five".