64820 has 24 divisors (see below), whose sum is σ = 155904. Its totient is φ = 22176.

The previous prime is 64817. The next prime is 64849. The reversal of 64820 is 2846.

64820 = T₃ + T₄ + ... + T₇₂.

It is a Harshad number since it is a multiple of its sum of digits (20).

It is a plaindrome in base 11.

It is a junction number, because it is equal to n+sod(n) for n = 64792 and 64801.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 64820.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 92 + ... + 371.

It is an arithmetic number, because the mean of its divisors is an integer number (6496).

2⁶⁴⁸²⁰ is an apocalyptic number.

It is an amenable number.

64820 is an abundant number, since it is smaller than the sum of its proper divisors (91084).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

It is a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (77952).

64820 is a wasteful number, since it uses less digits than its factorization.

64820 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 479 (or 477 counting only the distinct ones).

The product of its (nonzero) digits is 384, while the sum is 20.

The square root of 64820 is about 254.5977219065. The cubic root of 64820 is about 40.1701088820.

It can be divided in two parts, 6 and 4820, that multiplied together give a triangular number (28920 = T₂₄₀).

The spelling of 64820 in words is "sixty-four thousand, eight hundred twenty".