28626640 has 160 divisors (see below), whose sum is σ = 83994624. Its totient is φ = 8847360.

The previous prime is 28626607. The next prime is 28626649. The reversal of 28626640 is 4662682.

It is a Harshad number since it is a multiple of its sum of digits (34).

It is a junction number, because it is equal to n+sod(n) for n = 28626596 and 28626605.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28626649) by changing a digit.

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 31 ways as a sum of consecutive naturals, for example, 295072 + ... + 295168.

Almost surely, 2^28626640 is an apocalyptic number.

28626640 is a gapful number since it is divisible by the number (20) 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 28626640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (41997312).

28626640 is an abundant number, since it is smaller than the sum of its proper divisors (55367984).

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

28626640 is a wasteful number, since it uses less digits than its factorization.

28626640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 165 (or 159 counting only the distinct ones).

The product of its (nonzero) digits is 27648, while the sum is 34.

The square root of 28626640 is about 5350.3869018978. The cubic root of 28626640 is about 305.9075004850.

The spelling of 28626640 in words is "twenty-eight million, six hundred twenty-six thousand, six hundred forty".