64642820 has 24 divisors (see below), whose sum is σ = 148091328. Its totient is φ = 23506400.

The previous prime is 64642771. The next prime is 64642829. The reversal of 64642820 is 2824646.

It is a happy number.

It is not an unprimeable number, because it can be changed into a prime (64642829) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 146696 + ... + 147135.

It is an arithmetic number, because the mean of its divisors is an integer number (6170472).

Almost surely, 2^64642820 is an apocalyptic number.

It is an amenable number.

64642820 is an abundant number, since it is smaller than the sum of its proper divisors (83448508).

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

64642820 is a wasteful number, since it uses less digits than its factorization.

64642820 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 293851 (or 293849 counting only the distinct ones).

The product of its (nonzero) digits is 18432, while the sum is 32.

The square root of 64642820 is about 8040.0758702888. The cubic root of 64642820 is about 401.3347494888.

The spelling of 64642820 in words is "sixty-four million, six hundred forty-two thousand, eight hundred twenty".