28407940 has 24 divisors (see below), whose sum is σ = 65080512. Its totient is φ = 10330080.

The previous prime is 28407937. The next prime is 28407941. The reversal of 28407940 is 4970482.

It is a happy number.

It is a super-2 number, since 2×28407940² = 1614022110087200, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 28407896 and 28407905.

It is not an unprimeable number, because it can be changed into a prime (28407941) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 64344 + ... + 64783.

It is an arithmetic number, because the mean of its divisors is an integer number (2711688).

Almost surely, 2^28407940 is an apocalyptic number.

28407940 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

28407940 is an abundant number, since it is smaller than the sum of its proper divisors (36672572).

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

28407940 is a wasteful number, since it uses less digits than its factorization.

28407940 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 129147 (or 129145 counting only the distinct ones).

The product of its (nonzero) digits is 16128, while the sum is 34.

The square root of 28407940 is about 5329.9099429540. The cubic root of 28407940 is about 305.1264905782.

The spelling of 28407940 in words is "twenty-eight million, four hundred seven thousand, nine hundred forty".