64540220 has 24 divisors (see below), whose sum is σ = 138093984. Its totient is φ = 25328576.

The previous prime is 64540213. The next prime is 64540243. The reversal of 64540220 is 2204546.

It is a congruent number.

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, 29384 + ... + 31503.

It is an arithmetic number, because the mean of its divisors is an integer number (5753916).

Almost surely, 2^64540220 is an apocalyptic number.

It is an amenable number.

64540220 is an abundant number, since it is smaller than the sum of its proper divisors (73553764).

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

64540220 is a wasteful number, since it uses less digits than its factorization.

64540220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 60949 (or 60947 counting only the distinct ones).

The product of its (nonzero) digits is 1920, while the sum is 23.

The square root of 64540220 is about 8033.6927997030. The cubic root of 64540220 is about 401.1223064588.

Adding to 64540220 its reverse (2204546), we get a palindrome (66744766).

The spelling of 64540220 in words is "sixty-four million, five hundred forty thousand, two hundred twenty".