28503640 has 32 divisors (see below), whose sum is σ = 69964560. Its totient is φ = 10364800.

The previous prime is 28503617. The next prime is 28503649. The reversal of 28503640 is 4630582.

It is a junction number, because it is equal to n+sod(n) for n = 28503599 and 28503608.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28503649) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 31951 + ... + 32830.

Almost surely, 2^28503640 is an apocalyptic number.

28503640 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

28503640 is an abundant number, since it is smaller than the sum of its proper divisors (41460920).

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

28503640 is a wasteful number, since it uses less digits than its factorization.

28503640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 64803 (or 64799 counting only the distinct ones).

The product of its (nonzero) digits is 5760, while the sum is 28.

The square root of 28503640 is about 5338.8800323663. The cubic root of 28503640 is about 305.4687408584.

The spelling of 28503640 in words is "twenty-eight million, five hundred three thousand, six hundred forty".