28577640 has 128 divisors (see below), whose sum is σ = 105557760. Its totient is φ = 6027264.

The previous prime is 28577639. The next prime is 28577641. The reversal of 28577640 is 4677582.

It is an interprime number because it is at equal distance from previous prime (28577639) and next prime (28577641).

It is a Harshad number since it is a multiple of its sum of digits (39).

It is not an unprimeable number, because it can be changed into a prime (28577641) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 9612 + ... + 12228.

It is an arithmetic number, because the mean of its divisors is an integer number (824670).

Almost surely, 2^28577640 is an apocalyptic number.

28577640 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 28577640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (52778880).

28577640 is an abundant number, since it is smaller than the sum of its proper divisors (76980120).

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

28577640 is a wasteful number, since it uses less digits than its factorization.

28577640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2651 (or 2647 counting only the distinct ones).

The product of its (nonzero) digits is 94080, while the sum is 39.

The square root of 28577640 is about 5345.8058326131. The cubic root of 28577640 is about 305.7328609637.

The spelling of 28577640 in words is "twenty-eight million, five hundred seventy-seven thousand, six hundred forty".