64840020 has 96 divisors (see below), whose sum is σ = 208631808. Its totient is φ = 14739072.

The previous prime is 64840019. The next prime is 64840031. The reversal of 64840020 is 2004846.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 110167 + ... + 110753.

It is an arithmetic number, because the mean of its divisors is an integer number (2173248).

Almost surely, 2^64840020 is an apocalyptic number.

64840020 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 64840020, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (104315904).

64840020 is an abundant number, since it is smaller than the sum of its proper divisors (143791788).

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

64840020 is a wasteful number, since it uses less digits than its factorization.

64840020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 869 (or 867 counting only the distinct ones).

The product of its (nonzero) digits is 1536, while the sum is 24.

The square root of 64840020 is about 8052.3300975556. The cubic root of 64840020 is about 401.7424403990.

Adding to 64840020 its reverse (2004846), we get a palindrome (66844866).

The spelling of 64840020 in words is "sixty-four million, eight hundred forty thousand, twenty".