64128540 has 96 divisors (see below), whose sum is σ = 206599680. Its totient is φ = 14558976.

The previous prime is 64128509. The next prime is 64128563. The reversal of 64128540 is 4582146.

It is a super-2 number, since 2×64128540² = 8224939285063200, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a junction number, because it is equal to n+sod(n) for n = 64128498 and 64128507.

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, 74754 + ... + 75606.

It is an arithmetic number, because the mean of its divisors is an integer number (2152080).

Almost surely, 2^64128540 is an apocalyptic number.

64128540 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 64128540, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (103299840).

64128540 is an abundant number, since it is smaller than the sum of its proper divisors (142471140).

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

64128540 is a wasteful number, since it uses less digits than its factorization.

64128540 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1051 (or 1049 counting only the distinct ones).

The product of its (nonzero) digits is 7680, while the sum is 30.

The square root of 64128540 is about 8008.0297202246. The cubic root of 64128540 is about 400.2676125855.

The spelling of 64128540 in words is "sixty-four million, one hundred twenty-eight thousand, five hundred forty".