28622640 has 80 divisors (see below), whose sum is σ = 89280000. Its totient is φ = 7585536.

The previous prime is 28622639. The next prime is 28622651. The reversal of 28622640 is 4622682.

It is a tau number, because it is divible by the number of its divisors (80).

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 = 28622598 and 28622607.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 57111 + ... + 57609.

It is an arithmetic number, because the mean of its divisors is an integer number (1116000).

Almost surely, 2^28622640 is an apocalyptic number.

28622640 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 28622640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (44640000).

28622640 is an abundant number, since it is smaller than the sum of its proper divisors (60657360).

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

28622640 is a wasteful number, since it uses less digits than its factorization.

28622640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 754 (or 748 counting only the distinct ones).

The product of its (nonzero) digits is 9216, while the sum is 30.

The square root of 28622640 is about 5350.0130840962. The cubic root of 28622640 is about 305.8932516711.

The spelling of 28622640 in words is "twenty-eight million, six hundred twenty-two thousand, six hundred forty".