28401940 has 48 divisors (see below), whose sum is σ = 70019712. Its totient is φ = 9472896.

The previous prime is 28401937. The next prime is 28402007. The reversal of 28401940 is 4910482.

It is a Harshad number since it is a multiple of its sum of digits (28).

It is a junction number, because it is equal to n+sod(n) for n = 28401899 and 28401908.

It is a congruent number.

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, 2439 + ... + 7921.

It is an arithmetic number, because the mean of its divisors is an integer number (1458744).

Almost surely, 2^28401940 is an apocalyptic number.

28401940 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 28401940, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (35009856).

28401940 is an abundant number, since it is smaller than the sum of its proper divisors (41617772).

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

28401940 is a wasteful number, since it uses less digits than its factorization.

28401940 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5536 (or 5534 counting only the distinct ones).

The product of its (nonzero) digits is 2304, while the sum is 28.

The square root of 28401940 is about 5329.3470519380. The cubic root of 28401940 is about 305.1050072904.

The spelling of 28401940 in words is "twenty-eight million, four hundred one thousand, nine hundred forty".