64736820 has 120 divisors (see below), whose sum is σ = 205821000. Its totient is φ = 17031168.

The previous prime is 64736809. The next prime is 64736821. The reversal of 64736820 is 2863746.

64736820 is a `hidden beast` number, since 647 + 3 + 6 + 8 + 2 + 0 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 2862864 + 61873956 = 1692^2 + 7866^2 .

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (64736821) by changing a digit.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 143956 + ... + 144404.

It is an arithmetic number, because the mean of its divisors is an integer number (1715175).

Almost surely, 2^64736820 is an apocalyptic number.

64736820 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 64736820, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (102910500).

64736820 is an abundant number, since it is smaller than the sum of its proper divisors (141084180).

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

64736820 is a wasteful number, since it uses less digits than its factorization.

64736820 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 559 (or 548 counting only the distinct ones).

The product of its (nonzero) digits is 48384, while the sum is 36.

The square root of 64736820 is about 8045.9194626842. The cubic root of 64736820 is about 401.5291881757.

It can be divided in two parts, 64736 and 820, that added together give a palindrome (65556).

The spelling of 64736820 in words is "sixty-four million, seven hundred thirty-six thousand, eight hundred twenty".