64405620 has 36 divisors (see below), whose sum is σ = 195364260. Its totient is φ = 17174784.

The previous prime is 64405613. The next prime is 64405633. The reversal of 64405620 is 2650446.

It is a happy number.

64405620 is a `hidden beast` number, since 64 + 40 + 562 + 0 = 666.

64405620 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 2 ways, for example, as 33802596 + 30603024 = 5814^2 + 5532^2 .

It is a tau number, because it is divible by the number of its divisors (36).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 178725 + ... + 179084.

It is an arithmetic number, because the mean of its divisors is an integer number (5426785).

Almost surely, 2^64405620 is an apocalyptic number.

64405620 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

64405620 is an abundant number, since it is smaller than the sum of its proper divisors (130958640).

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

64405620 is a wasteful number, since it uses less digits than its factorization.

64405620 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 357824 (or 357819 counting only the distinct ones).

The product of its (nonzero) digits is 5760, while the sum is 27.

The square root of 64405620 is about 8025.3112089189. The cubic root of 64405620 is about 400.8432626875.

It can be divided in two parts, 64405 and 620, that added together give a square (65025 = 255²).

The spelling of 64405620 in words is "sixty-four million, four hundred five thousand, six hundred twenty".