28293040 has 40 divisors (see below), whose sum is σ = 66589488. Its totient is φ = 11178240.

The previous prime is 28293019. The next prime is 28293073. The reversal of 28293040 is 4039282.

28293040 = 25² + 26² + ... + 439².

It is a tau number, because it is divible by the number of its divisors (40).

It is a super-2 number, since 2×28293040² = 1600992224883200, which contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4510 + ... + 8770.

Almost surely, 2^28293040 is an apocalyptic number.

28293040 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 28293040, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (33294744).

28293040 is an abundant number, since it is smaller than the sum of its proper divisors (38296448).

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

28293040 is a wasteful number, since it uses less digits than its factorization.

28293040 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4357 (or 4351 counting only the distinct ones).

The product of its (nonzero) digits is 3456, while the sum is 28.

The square root of 28293040 is about 5319.1202280076. The cubic root of 28293040 is about 304.7145587102.

The spelling of 28293040 in words is "twenty-eight million, two hundred ninety-three thousand, forty".